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Question P6 Everything changed

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Emma and Lily's savings — 2 : 1 becomes 4 : 1

The ratio of Emma’s savings to Lily’s savings was 2:1. After Emma saved $60 and Lily spent $30, the new ratio became 4:1. How much money did Emma have at first?

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About this method

Everything changed

Both amounts change, so no total and no gap stays fixed.

In this one. Both quantities changed, so a unit of the ratio at first and a part of the ratio at the end are different sizes — swap every unit for 1 part + 30 (Lily's change) and Emma's whole equation becomes one in parts alone.

Beforetotal 7, gap 1AliBenAftertotal 8, gap 4 — both movedAlispent 1Bensaved 2

How to spot it

Both people in a ratio change by different amounts, with words like 'joined' or 'saved more' for one and 'left' or 'spent' for the other.

Common mistake

Children look for a fixed total or a fixed gap out of habit. Neither is fixed here, so only the ratio at the end can give the size of a share.

Practise a similar question

Challenging The ratio of Ali’s money to Billy’s money was 2 : 1. After Ali saved another $60 and Billy spent $150, the ratio became 4 : 1. How much money did Ali have at first?
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