In April, Ben gave his wife, Mary, $7500 for household expenditure. Mary spent 50% of the sum on rental, 10% on food and saved the rest. In May, Ben reduced the sum he gave to Mary. Mary spent the same amount on rental and reduced the amount she spent on food by 30%. She saved the remaining 25% of the sum given to her in May. By what percentage was the sum given to Mary reduced by?

	Rental	Food	Savings	Total
Before	50%	10%	40%	$7500
Change		- 3%	- ?	- ?
After	50%	7%
Comparing the amounts spent in May	75 u		25 u	100 u

Amount that Ben saved in percent
= 100% - 50% - 10%
= 40%

Amount that Ben reduced on food in percent
= 30% x 10%
= ³⁰₁₀₀ x 10
= 3%

Total amount that Ben spent on rental and food in percent
= 50% + 7%
= 57%

100% → 7500

1% → 7500 ÷ 100 = 75

57% → 57 x  75 = 4275

The total amount that Ben spent on rental and food is repeated. 

75 u = 57% 

75 u = 4275

1 u = 4275 ÷ 75 = 57

Amount that Ben gave to Mary in May
= 100 u
= 100 x 57
= $5700

Amount that Mary received less from Ben from April to May
= 7500 - 5700
= $1800

Percentage that the sum given to Mary was reduced by from April to May
= ¹⁸⁰⁰₇₅₀₀ x 100%
= 24%

Answer(s): 24%