The ratio between sugar and water is 5 : 7. If sugar is 35, then water is:

Correct answer: 49. Sugar 35 = 5 × 7, so water = 7 × 7 = 49.

Background: Multiply both parts of the ratio by the same number.

• 42: 42 is 7 × 6.
• 56: 56 is 7 × 8.
• 63: 63 is 7 × 9.

Did you know? The multiplier is 35 ÷ 5 = 7.

Memory trick: Same multiplier on both parts.