MathBrush

Practice

Same pattern as Ali and Ben's savings — the ratio shifts. New numbers, new story. Try each one on paper, then check the working below — or watch it drawn out, the same way the problem above is.

Question 1

Mei and Sam collect stickers. The ratio of Mei's stickers to Sam's stickers was 2 : 3. Mei then received 18 more stickers as a gift, so the ratio became 5 : 6. How many stickers did Mei have at first?

Work it out on paper, then check below. ▶ See the working

Question 2

The ratio of Ravi's marbles to Tom's marbles was 5 : 8. Ravi then bought 20 more marbles, so the ratio became 3 : 4. How many marbles did Ravi have at first?

Work it out on paper, then check below. ▶ See the working

Question 3

Tank X and Tank Y held water in the ratio 7 : 9. More water was then poured into Tank X only, 4 litres worth, so the ratio became 4 : 5. How many litres did Tank X hold at first?

Work it out on paper, then check below. ▶ See the working

The working