Question

Alice's stamp collection was 75% of the size of Raymond's. After Alice sold 40% of her stamps and Raymond sold 20% of his stamps, Alice had 140 fewer stamps than Raymond. How many stamps did Alice sell?

Answer 1

Raymond's stamp collection ➞x
Alice′s stamp collection➞75%x
75%x-40%×75%x+140=x-20%x
75%x-30%x+140=80%x
45%x+140=80%x
140=80%x-45%x
x=400
Raymond′s stamp collection ➞400
Alice′s stamp collection➞300
Alice sold 300×40%=120
Answer:120