1. , , Ratios and Unit Rates Write three fractions equivalent to . 6-1 4
PRE-ALGEBRA LESSON 6-1 4 12
Write three fractions equivalent to .
, , 6 18 1 3 2
Sample answers
6-1

2. Ratios and Unit Rates Write in simplest form. 1. 2. 3. 4. 5. 6. 6-1 30
PRE-ALGEBRA LESSON 6-1
(For help, go to Lesson 4-4.)
Write in simplest form. 30 35 24 40 54 60 12 15 14 42 40 24
Check Skills You’ll Need
6-1

3. Ratios and Unit Rates Solutions 1. = 2. = = = 3. = 4. = 5. = 6. =
PRE-ALGEBRA LESSON 6-1
Solutions 30 35
30 ÷ 5
35 ÷ 5 24 40
24 ÷ 8
40 ÷ 8
= =
= =
= =
= =
= = = 1 6 7 3 5 54 60
54 ÷ 6
60 ÷ 6 12 15
12 ÷ 3
15 ÷ 3 9 10 4 5 14 42
14 ÷ 14
42 ÷ 14 40 24
40 ÷ 8
24 ÷ 8 1 3 5 3 2 3
6-1

4. a. all students surveyed to students without jobs After-School Jobs
Ratios and Unit Rates
PRE-ALGEBRA LESSON 6-1
A survey asked students whether they had after-school jobs. Write each ratio as a fraction in simplest form.
a. all students surveyed to students
without jobs
After-School Jobs
Response
Number
Have a Job 40 60
100
Don’t Have a Job
Total
all students surveyed
students without jobs
100 60 = = 5 3
b. all students surveyed to students
with jobs
all students surveyed
students with jobs
100 40 = = 5 2
Quick Check
6-1

5. The 50-card pack has the lowest unit price.
Ratios and Unit Rates
PRE-ALGEBRA LESSON 6-1
The table shows prices for different packages of index cards. Which size has the lowest unit price?
Price
$2.70
$1.30
$.75
100 50 25
Size
(cards)
100 cards:
price
number of cards
$2.70
100 cards
= $.027/card
50 cards:
price
number of cards
$1.30
50 cards
= $.026/card
Find the unit prices.
25 cards:
price
number of cards
$0.75
25 cards
= $.03/card
Quick Check
The 50-card pack has the lowest unit price.
6-1

6. Convert 30 gal/min to cups/second.
Ratios and Unit Rates
PRE-ALGEBRA LESSON 6-1
Convert 30 gal/min to cups/second.
30 gal/min = • •
30 gal
1 min
16 c
1 gal
60 s
Use conversion factors that convert gallons to cups and minutes to seconds.
1 min
1260 s
Divide the common factors
and units.
= • •
130 gal
816 c
1 gal =
8 c s
Simplify.
30 gal/min equals 8 c/s.
Quick Check
6-1

7. Write each ratio as a fraction in simplest form.
Ratios and Unit Rates
PRE-ALGEBRA LESSON 6-1
Write each ratio as a fraction in simplest form.
1. 4 out of 20 students ride the bus to school.
2. 8 out of 10 students buy lunch.
Find each unit rate.
3. You pay $4.50 for 2 gallons of orange juice.
4. You pay $21.60 for a 20-lb bag of dog food.
5. Convert 15 yd/min to inches/second. 1 5 4 5
$2.25/gal
$1.08/lb
9 in./s
6-1

8. Evaluate each of the following operations for n = 6.
Proportions
PRE-ALGEBRA LESSON 6-2
Evaluate each of the following operations for n = 6.
a. Multiply n by 4 and add b. Multiply n by 9 and add 12 30 66
6-2

9. Proportions Solve each equation. 1. 4x = 52 2. 3y = 18
PRE-ALGEBRA LESSON 6-2
(For help, go to Lesson 2-6.)
Solve each equation.
1. 4x = y = 18
3. 5b = k = 21
Check Skills You’ll Need
6-2

10. = = = = Proportions Solutions 1. 4x = 52 2. 3y = 18 x = 13 y = 6
PRE-ALGEBRA LESSON 6-2
Solutions
1. 4x = y = 18
x = y = 6
3. 5b = k = 21
b = k = 3 4x 4 52 4 3y 3 18 3 = = 5b 5 75 5 7k 7 21 7 = =
6-2

11. Method 1 Multiplication Property of Equality
Proportions
PRE-ALGEBRA LESSON 6-2 2 7 y 14
Solve =
Method 1 Multiplication Property of Equality = 2 7 y 14
• 14 = • 14 2 7 y 14
= y 28 7
4 = y
6-2

12. Proportions (continued) Method 2 Cross products = 2 • 14 = 7 • y
PRE-ALGEBRA LESSON 6-2
(continued)
Method 2 Cross products = 2 7 y 14
2 • 14 = 7 • y
28 = 7y = 28 7 7y
4 = y
Quick Check
6-2

13. Do the ratios and form a proportion? Explain.
Proportions
PRE-ALGEBRA LESSON 6-2
Do the ratios and form a proportion? Explain. 3 5 21 35
Test by writing as a proportion. 3 5 21 35
3 • • 21
Write cross products.
105 = 105 Simplify.
Yes; the ratios do form a proportion. The cross products are equal.
Quick Check
6-2

14. Let d = distance in fathoms.
Proportions
PRE-ALGEBRA LESSON 6-2
One hundred rods is about 275 fathoms. About how many fathoms is 25 rods?
Let d = distance in fathoms.
length in rods
length in fathoms
100
275 = 25 d
distance in rods
distance in fathoms
100d = 275(25) Write cross products.
d = Divide each side by 100.
275(25)
100
d = Simplify.
25 rods is about fathoms.
Quick Check
6-2

15. Does each pair of ratios form a proportion? Explain. 3. 4.
Proportions
PRE-ALGEBRA LESSON 6-2
Solve each proportion.
1. 2.
Does each pair of ratios form a proportion? Explain.
3. 4.
nautical miles equals about 115 statute miles. About how far in ` nautical miles is 50 statute miles? Round to the nearest whole number. a 12 5 6 3 8 6 x = 10 = 16 2 9
0.4
1.8 21 50 14 25 = =
Yes; the cross products are equal.
No; the cross products are not equal.
about 43 nautical miles
6-2

16. Similar Figures and Scale Drawings
PRE-ALGEBRA LESSON 6-3
Find each value of n.
a b. 18 15 = n 5 n
2.7
1.5
4.5 =
n = 6
n = 0.9
6-3

17. Similar Figures and Scale Drawings
PRE-ALGEBRA LESSON 6-3
(For help, go to Lesson 6-2.)
Solve each proportion. Round to the nearest tenth where necessary. 2 3 f 21 3 8 50 p = = 9 4 15 p 16 3 19 g = =
Check Skills You’ll Need
6-3

18. Similar Figures and Scale Drawings
PRE-ALGEBRA LESSON 6-3
Solutions 1. 2 3 f 21 =
3 • f = 2 • 21
3f = 42 3f 42
f = 14 3 8 50 p =
8 • 50 = 3 • p
400 = 3p
400 3p
133.3 = p 2. 3. 9 4 15 p =
4 • 15 = 9 • p
60 = 9p 60 9p
6.7 = p 4. 16 3 19 g =
3 • 19 = 16 • g
57 = 16g 57
16g
3.6 = g
6-3

19. Similar Figures and Scale Drawings
PRE-ALGEBRA LESSON 6-3
Trapezoid ABCD ~ trapezoid EFGH. Find the value of k.
Write a proportion for corresponding sides. 6 k
Side AB corresponds = Side CD corresponds
to side EF. to side GH. 3 2
6 • 2 = k • 3 Write cross products.
= Divide each side by 3.
6 • 2 3 3k
4 = k Simplify.
Quick Check
6-3

20. Similar Figures and Scale Drawings
PRE-ALGEBRA LESSON 6-3
A flagpole casts a shadow 5 ft long. At the same time, a yardstick casts a shadow 1.5 ft long. The triangle shown for the flagpole and its shadow is similar to the triangle shown for the yardstick and its shadow. How tall is the flagpole?
Corresponding sides of similar triangles are in proportion.
1.5 5 = 3 x
1.5x = 5 • 3   Write cross products.
Divide each side by 1.5.
1.5x
1.5 =
5 • 3
x = 10   Simplify.
The flagpole is 10 ft tall.
Quick Check
6-3

21. Similar Figures and Scale Drawings
PRE-ALGEBRA LESSON 6-3
The scale of a map is 1 in. : 24 mi. About how far is it between two cities that are 3 in. apart on the map?
map (in.)
actual (mi.) 1 24 3 d =
Write a proportion.
1 • d = 24 • 3
Write cross products.
d = 72
Simplify.
It is about 72 mi between the two cities.
Quick Check
6-3

22. Similar Figures and Scale Drawings
PRE-ALGEBRA LESSON 6-3
Solve.
1. Parallelogram ABCD ~ parallelogram EFGH.
Find the value of x.
2. A girl who is 4 feet tall casts a shadow that is 6 feet long. The tree next to her casts a shadow that is 12 feet long. How tall is the tree?
3. The scale on a map is 3 in. : 100 mi. What is the actual distance between two towns that are 9 in. apart on the map? 12
8 ft
300 mi
6-3

23. Probability
PRE-ALGEBRA LESSON 6-4
Forty-three boys and five girls tried out for the middle school football
team. One-fourth of the students were dropped after the first day. Of those who were left, were dropped after the second day. Of those who remained, made the team. How many students made
the team? 1 6 4 5 24
6-4

24. Probability Simplify. 1. 1 – 2. 1 – 3. 1 – 4. 1 – 6-4 3 17 8 20 6 1 11
PRE-ALGEBRA LESSON 6-4
(For help, go to Lesson 5-3.)
Simplify.
1. 1 – –
3. 1 – – 3 8 17 20 6 11 1 12
Check Skills You’ll Need
6-4

25. Probability Solutions 1. 1 – 2. 1 – – = – = = = 3. 1 – 4. 1 – – = – =
PRE-ALGEBRA LESSON 6-4
Solutions
– –
– = – =
= =
– –
– = – =
= = 3 8 17 20
8 – 3
20 – 17 5 6 11 1 12
11 – 6
12 –1
6-4

26. Find P(rolling a prime number) with one number cube.
Probability
PRE-ALGEBRA LESSON 6-4
Find P(rolling a prime number) with one number cube. =
number of favorable outcomes
number of possible outcomes 3 6
3 prime-number outcomes (2, 3, 5)
6 possible outcomes
P(rolling a prime number) = , or . 3 6 1 2
Quick Check
6-4

27. P(not an identical twin) + P(identical twin) = 1 Write an equation.
Probability
PRE-ALGEBRA LESSON 6-4
The probability that a child is an identical twin is 4 in 1,000. Find P(not an identical twin).
P(not an identical twin) + P(identical twin) = 1  Write an equation.
P(not an identical twin) + = 1  Substitute. 4
1,000
P(not an identical twin) + – = 1  – Subtract from each side. 4
1,000
996
1,000
P(not an identical twin) =   Simplify. =
249
250
The probability that a child is not an identical twin is .
249
250
Quick Check
6-4

28. 2 are worth less than ten cents. 3 are not.
Probability
PRE-ALGEBRA LESSON 6-4
You have five different coins in your pocket: a penny, a nickel, a dime, a quarter, and a half-dollar. You pull out one coin at random. What are the odds in favor of the coin being worth less than ten cents?
odds in favor = 2 3
2 are worth less than ten cents.
3 are not.
The odds are , or 2 to 3, in favor of the coin being worth less than ten cents. 2 3
Quick Check
6-4

29. 3. When rolling a number cube, what is P(6)? What is P(not 6)?
Probability
PRE-ALGEBRA LESSON 6-4
Find each probability.
1. A letter is selected at random from the letters A, E, I, O, and U. Find the probability that the letter is an A.
2. In one class, Ms. Lang has 8 boys and 12 girls. She needs to choose one student to help pass out papers. What are the odds that a girl is chosen?
3. When rolling a number cube, what is P(6)? What is P(not 6)? 1 5 3 2 ; 1 6 5
6-4

30. Fractions, Decimals, and Percents
PRE-ALGEBRA LESSON 6-5 5 8
Samantha needs a -in. bit for her drill. Should she look in the bin
marked 62.5 in., 6.25 in., in., or in.?
0.625 in.
6-5

31. Fractions, Decimals, and Percents
PRE-ALGEBRA LESSON 6-5
(For help, go to Lesson 5-2.)
Write each fraction as a decimal. 5 8 9 20 3 4 5 6 2 3 8 11
Check Skills You’ll Need
6-5

32. Fractions, Decimals, and Percents
PRE-ALGEBRA LESSON 6-5
= 5 ÷ = 9 ÷ = 3 ÷ 4
= = = 0.75
= 5 ÷ = 2 ÷ = 8 ÷ 11
= = = 0.72 9 20 8 11 3 4
Solutions 5 6 2
6-5

33. Fractions, Decimals, and Percents
PRE-ALGEBRA LESSON 6-5
Write each percent as a fraction or a mixed number.
a. 30%
Write as a fraction with a denominator of 100. 30
100
Simplify. 3 10
b. 175%
Write as a fraction with a denominator of 100.
175
100
Simplify. 7 4
1 Write as a mixed number. 3 4
Quick Check
6-5

34. Fractions, Decimals, and Percents
PRE-ALGEBRA LESSON 6-5
Express 7.3% as a decimal.
7.3% = Write as a fraction with a denominator of 100.
7.3
100
= 007.3   Divide by moving the decimal point two places to
the left. You may need to write one or more zeros.
= 0.073
Quick Check
6-5

35. Fractions, Decimals, and Percents
PRE-ALGEBRA LESSON 6-5
Express as a percent.
Method 1 Rewrite as a fraction.
0.412 =
412
1,000 =
412 ÷ 10
1,000 ÷ 10 =
41.2
100
= 41.2%
Method 2 Move the decimal point.
0.412 = 41.2%
Quick Check
6-5

36. Fractions, Decimals, and Percents
PRE-ALGEBRA LESSON 6-5
Four out of seven members of the chess club are boys. What percent of the chess club members are boys?
Write a fraction. 4 7
Divide the numerator by the denominator.
57.14%   Write as a percent.
About 57% of the chess club members are boys.
Quick Check
6-5

37. Fractions, Decimals, and Percents
PRE-ALGEBRA LESSON 6-5
Write each percent as a fraction or mixed number, and as a decimal.
1. 325% %
Write each as a percent.
5. Six out of fifteen students own skateboards. What percent of students own skateboards? 13 4
, or 3 ; 3.25 1 11
1,000
; or 0.011 3 5
201%
60%
40%
6-5

38. Proportions and Percents
PRE-ALGEBRA LESSON 6-6
A painter uses 3 cans of paint to paint four sets of shelves. How many
cans of paint does he need to buy to paint nine sets of shelves?
7 cans
6-6

39. Proportions and Percents
PRE-ALGEBRA LESSON 6-6
(For help, go to Lesson 6-2.)
Solve each proportion.
= =
= = 25
100 x 28
98.9 x 43
100 52
100 13 x x
100 27
150
Check Skills You’ll Need
6-6

40. Proportions and Percents
PRE-ALGEBRA LESSON 6-6
Solutions 25
100 x 28
98.9 x 43
100
1. = 2. =
100 • x = 25 • • x = 98.9 • 100
100x = x = 9890
= =
x = x = 230
= =
13 • 100 = 52 • x • 27 = x • 150
1300 = 52x = 150x
= =
25 = x = x
100x
100
700
100
43x 43
9890 43 52
100 13 x x
100 27
150
1300 52
52x 52
2700
150
150x
150
6-6

41. Proportions and Percents
PRE-ALGEBRA LESSON 6-6
Find 23% of 158.
= Write a proportion. 23
100 n
158
23(158) = 100n Write cross products.
=    Divide each side by 100.
23(158)
100
100n
36.34 = n Simplify.
23% of 158 is
Quick Check
6-6

42. Proportions and Percents
PRE-ALGEBRA LESSON 6-6
What percent of 34 is 28? Round to the nearest tenth of a percent.
= Write a proportion. n
100 28 34
34n = 100(28) Write cross products.
=    Divide each side by 34.
100(28) 34
34n
n = Simplify.
82.4 Round.
28 is approximately 82.4% of 34.
Quick Check
6-6

43. Proportions and Percents
PRE-ALGEBRA LESSON 6-6
216 is 72% of what number?
= Write a proportion. 72
100
216 n
72n = 100(216) Write cross products.
=    Divide each side by 72.
100(216) 72
72n
n = 300 Simplify.
216 is 72% of 300.
Quick Check
6-6

44. Proportions and Percents
PRE-ALGEBRA LESSON 6-6
A tile floor has 90 blue tiles, which is 15% of all the tiles in the floor. How many tiles are in the floor in all?
= Write a proportion. 15
100 90 x
15x = 100(90) Write cross products.
=    Divide each side by 15.
100(90) 15
15x
x = 600 Simplify.
The floor has 600 tiles in all.
Check. Is the answer reasonable? The problem says the number of
blue tiles is 15%. 10% of 600 is 60, so 5% of 600 is 30, and
15% is = 90. The answer is reasonable.
Quick Check
6-6

45. Proportions and Percents
PRE-ALGEBRA LESSON 6-6
Solve.
1. Find 47% of 2, What percent of 700 is 1,498?
3. 6 is 3% of what number?
4. Water covers about 361,736,000 km2, or about 70.8% of Earth’s surface. What is the approximate surface area of Earth?
1,128
214%
200
about 511,000,000 km2
6-6

46. Percents and Equations
PRE-ALGEBRA LESSON 6-7
Match each expression in Column 1 with an equivalent expression in Column 2.
Column Column 2
1. 50% of a. 250
2. 100% of b. 2.5
3. 1% of c. 25
4. 10% of d. 125
1. d 2. a 3. b 4. c
6-7

47. Percents and Equations
PRE-ALGEBRA LESSON 6-7
(For help, go to Lesson 6-5.)
Write each percent as a decimal.
1. 48% 2. 5% %
% % %
Check Skills You’ll Need
6-7

48. Percents and Equations
PRE-ALGEBRA LESSON 6-7
% = % =
= = 0.05
% = % =
= =
% = % =
= = 1.785
Solutions 48
100 5
23.8
72.25
136
178.5
6-7

49. Percents and Equations
PRE-ALGEBRA LESSON 6-7
What is 35% of 84?
n = 0.35 • 84   Write an equation. Write the percent as a decimal.
n = Simplify.
35% of 84 is 29.4.
Quick Check
6-7

50. Percents and Equations
PRE-ALGEBRA LESSON 6-7
What percent of 26 is 65?
n • 26 = 65 Write an equation.
= Divide each side by 26.
26n 26 65
n = 2.5 Simplify.
= 250%   Change the decimal to a percent.
65 is 250% of 26.
Quick Check
6-7

51. Percents and Equations
PRE-ALGEBRA LESSON 6-7
A car salesman makes a 6.5% commission on each car he sells. How much does he make on the sale of a car for $35,000?
amount of
commission
Words is 6.5% of $35,000
Let c = amount of commission.
Equation = • $35,000 c
c = • 35,000
= 2,275
The salesman’s commission is $2,275.
Quick Check
6-7

52. Percents and Equations
PRE-ALGEBRA LESSON 6-7
During a telephone survey, 414 people, or 46% of those called, said that they were watching station RFGT at the time of the call. How many people were called?
Words is % of people called
Let n = number of people called.
Equation 414 = 0.46 • n
0.46n = 414 =
0.46n
0.46
414
n = 900
Quick Check
900 people were called.
6-7

53. Percents and Equations
PRE-ALGEBRA LESSON 6-7
Solve
1. What is 9% of 30? What is 25% of 312?
3. What percent of 9 is 3? 4. What percent of 3 is 9?
5. A car dealer makes an 8% commission on each car she sells. How much does she make on a $40,000 sale?
6. During a telephone survey, 320 people, or 25% of those called, said they were listening to the same station at the time of the call. How many people were called?
2.7 78
33 % 1 3
300%
$3,200
1,280 people
6-7

54. Write these fractions to the nearest tenth of a percent. a. b.
Percent of Change
PRE-ALGEBRA LESSON 6-8
Write these fractions to the nearest tenth of a percent.
a b. 65
255 42 52
25.5%
80.8%
6-8

55. Write each decimal as a percent. 1. 0.46 2. 2.47 3. 0.03 4. 5.236
Percent of Change
PRE-ALGEBRA LESSON 6-8
(For help, go to Lesson 6-5.)
Write each decimal as a percent.
Check Skills You’ll Need
6-8

56. 1. Move the decimal 2 places to the right. 0.46 = 46% 2. 2.47 = 247%
Percent of Change
PRE-ALGEBRA LESSON 6-8
Solutions
1. Move the decimal 2 places to the right = 46%
= 247%
= 3%
= 523.6%
6-8

57. Find the percent of increase from 8 to 9.6.
Percent of Change
PRE-ALGEBRA LESSON 6-8
Find the percent of increase from 8 to 9.6.
amount of increase = 9.6 – 8 = 1.6
percent of increase =
amount of increase
original amount =
1.6 8
= 0.2 = 20%
The percent of increase from 8 to 9.6 is 20%.
Quick Check
6-8

58. The percent of increase from March 1 to July 1 was 200%.
Percent of Change
PRE-ALGEBRA LESSON 6-8
In a given year, Hillsboro had a total of 7.5 in. of rain by March 1 and a total of 22.5 in. by July 1. Find the percent of increase from 7.5 to 22.5.
amount of increase = 22.5 – 7.5 = 15
percent of increase =
amount of increase
original amount = 15
7.5
= 2 = 200%
The percent of increase from March 1 to July 1 was 200%.
Quick Check
6-8

59. Find the percent of decrease from 1,250 to 1,120.
Percent of Change
PRE-ALGEBRA LESSON 6-8
Find the percent of decrease from 1,250 to 1,120.
amount of decrease = 1,250 – 1,120 = 130
percent of decrease =
amount of decrease
original amount =
130
1,250
= = 10.4%
Quick Check
6-8

60. 1. Find the percent of increase from 22 to 63.
Percent of Change
PRE-ALGEBRA LESSON 6-8
Solve.
1. Find the percent of increase from 22 to 63.
2. Find the percent of decrease from 6.3 to 2.2.
3. A surgeon performed 62 operations in He performed
342 in Find the percent of increase.
186.4%
65.1%
451.6%
6-8

61. Without computing, explain why 40% of 22 is less than 11.
Markup and Discount
PRE-ALGEBRA LESSON 6-9
Without computing, explain why 40% of 22 is less than 11.
11 is half, or 50%, of 22, so 40% of 22 is less than 11.
6-9

62. Write an equation and solve. Round to hundredths as needed.
Markup and Discount
PRE-ALGEBRA LESSON 6-9
(For help, go to Lesson 6-7.)
Write an equation and solve. Round to hundredths as needed.
1. What is 75% of $82?
2. What is 42% of $170?
3. What is 5.5% of $24?
4. What is 80% of $15.99?
Check Skills You’ll Need
6-9

63. 1. What is 75% of $82? 2. What is 42% of $170?
Markup and Discount
PRE-ALGEBRA LESSON 6-9
Solutions
1. What is 75% of $82? 2. What is 42% of $170?
n = 0.75 • 82 n = 0.42 • 170
n = n = 71.4
75% of $82 is $ % of $170 is $71.40.
3. What is 5.5% of $24? 4. What is 80% of $15.99?
n = • 24 n = 0.80 • 15.99
n = n = 12.79
5.5% of $24 is $ % of $15.99 is $12.79.
6-9

64. markup = percent of markup • store’s cost
Markup and Discount
PRE-ALGEBRA LESSON 6-9
A grocery store has a 20% markup on a can of soup. The can of soup costs the store $1.25. Find the markup.
markup = percent of markup • store’s cost
= 0.2 • 1.25  
= 0.25        Simplify.
The markup is $.25.
Quick Check
6-9

65. 0.45 • 4.50 = 2.03 Multiply to find the markup.
Markup and Discount
PRE-ALGEBRA LESSON 6-9
A bookstore pays $4.50 for a novel. The percent of markup is 45%. Find the novel’s selling price.
0.45 • 4.50 = 2.03 Multiply to find the markup.
= 6.53   Store’s cost + markup = selling price.
The selling price is $6.53.
Quick Check
6-9

66. discount = percent of discount • regular price
Markup and Discount
PRE-ALGEBRA LESSON 6-9
A camera that regularly sells for $210 is on sale for 30% off. Find the discount.
discount = percent of discount • regular price
= 0.30 • 210
= 63
The discount is $63.
Quick Check
6-9

67. Markup and Discount Solve.
PRE-ALGEBRA LESSON 6-9
Solve.
1. The school store has a 65% markup on each stapler. Each stapler costs the store $2.10. Find the markup.
2. A clothes store pays $40 for a skirt. The percent of markup is 25%. Find the skirt’s selling price.
3. A pair of shoes that regularly sells for $94.99 is on sale for 30% off. What is the sale price?
$1.37
$50
$66.49
6-9

68. Problem Solving Strategy: Make a Table
PRE-ALGEBRA LESSON 6-10
A theater has 25 seats in the first row. Each of the following rows
has two more seats than the row before it. How many seats are in
the 15-row theater?
585
6-10

69. Problem Solving Strategy: Make a Table
PRE-ALGEBRA LESSON 6-10
(For help, go to Lesson 1-8.)
Solve.
1. For two weeks, you double the amount of money you save each day. You save $.01 the first day. How much money will you have at the end of the two weeks?
Check Skills You’ll Need
6-10

70. Problem Solving Strategy: Make a Table
PRE-ALGEBRA LESSON 6-10
Solutions
Day Amount of new money saved Total amount saved
1 $.01 $.01
2 $ = $.03
3 $ = $.07
4 $ = $.15
5 $ = $.31
6 $ = $.63
7 $ = $1.27
8 $ = $2.55
9 $ = $5.11
10 $ = $10.23
11 $ = $20.47
12 $ = $40.95
13 $ = $81.91
14 $ = $163.83
After 2 weeks, $ will have been saved.
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71. Problem Solving Strategy: Make a Table
PRE-ALGEBRA LESSON 6-10
Martin had 100 trees in his orchard the first year. Each year after that he increased the number of trees in his orchard by 10%, rounded to the nearest whole number. How many trees did he have in his orchard in the sixth year?
Year Tree Count at Rate of Increase in Tree Count at
Beginning of Increase Tree Count End of Year
Year (10%)
6 161
Quick Check
Martin had 161 trees in the sixth year.
6-10

72. Problem Solving Strategy: Make a Table
PRE-ALGEBRA LESSON 6-10
Solve.
1. For an auction item, the bid starts at $100 and increases 50% every minute. In how many minutes will the bid go over $2,500?
2. Sharon uses her initials, SLF, for her password. How many different three-letter passwords can she make with these letters?
3. In how many ways can you make 45¢ in change using only nickels, dimes, and quarters?
8 minutes
6 passwords
8 ways
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