Question

Andrew has a salary of £250. He shares his salary with his sister in the ratio 2:3 every week. He saves 12% each week. How many weeks will it take for him to save £360?

Answer 1

A = Andrew
S = Sister

A : S
2 : 3
2 + 3 = 5
250 ÷ 5 = 50
2 × 50 = 100
3 × 50 = 150

∴ A : S
   100 : 150
So Andrew keeps £100 of his salary every week.

Of this, he saves 12%:
100 × (12 ÷ 100) = 12
So he saves £12 every week

360 ÷ 12 = 30
∴ it will take him 30 weeks to save £360.