Percentage related question I was solving following question: Last year Elaine spent 20% of her annual earnings on rent. This year she earned 15% more than last year and she spent 30% of her annual earnings on rent. The amount she spent on rent this year is what percent of the amount spent on rent last year? The answer that I found was 172%. But that book had 170% as the answer. Tell me what am I doing wrong? if x is her annual earning in year 1. the rent in year 1 will be 0.2x income in year 2 is 1.15x then rent in year 2 will be 0.3 * 1.15x = 0.345x and (0.345x / 0.2x)* 100 = 172.5 % please help.

Well from what I see there is no problem with your answer.