1. Finding an unknown quantity in a given Ratio (a) A fruit drink is made by mixing lemon squash with water in the ratio 4:5. How much water needs to be added to 28cl of lemon squash to make the drink? (b) To make Squirrel Grey paint, you need to mix Snow White and Beetle Black together in a ratio of 3:2. How much Snow White will you need if you’re using 18 litres of Beetle Black? x 7 5 4 SQUASH : WATER 28cl x 7 : : ? 35cl Therefore, 35cl of water needs to be added to make the drink. x 9 2 3 WHITE : BLACK 18litres x 9 : : ? 27litres Therefore, 27litres of Snow White needs to be mixed to make Squirrel Grey. 28 ÷ 4 18 ÷ 2

2. Finding an unknown quantity in a given Ratio The ratio of female to male members of a tennis club is 3 : 8. The total number of females in the club is 51. How many members are male? x 17 8 3 FEMALE : MALE 51 x 17 : : ? 136 Therefore, 136 members of the tennis club are male. 51 ÷ 3

3. Ques 1 In a room, the ratio of men to women is 4:1. If there are 20 men, how many women are there? TRUE – STAND UP FALSE – STAY PUT 5 women

4. Ques 2 In a shop the ratio of oranges to apples is 2:5. If there are 60 apples, how many oranges are there? TRUE – STAND UP FALSE – STAY PUT 84 oranges

5. Ques 3 In a train the ratio of adults to children is 7:2. If there are 126 adults, how many children are there? TRUE – STAND UP FALSE – STAY PUT 36 children

6. Ques 4 In a room, the ratio of men to women is 7:2. If there are 42 men, how many women are there? TRUE – STAND UP FALSE – STAY PUT 12 women

7. Ques 5 In a box, the ratio of nails to screws is 8:4. If there are 16 screws, how many nails are there? TRUE – STAND UP FALSE – STAY PUT 10 nails

8. Ques 6 An alloy consists of copper, zinc and tin in the ratios 2:3:5. If there is 20g of copper, there are 30g of zinc and 50g of tin. TRUE – STAND UP FALSE – STAY PUT