In April, Pierre gave his wife, Zara, $8000 for household expenditure. Zara spent 60% of the sum on rental, 10% on food and saved the rest. In May, Pierre reduced the sum he gave to Zara. Zara spent the same amount on rental and reduced the amount she spent on food by 30%. She saved the remaining 20% of the sum given to her in May. By what percentage was the sum given to Zara reduced by?

	Rental	Food	Savings	Total
Before	60%	10%	30%	$8000
Change		- 3%	- ?	- ?
After	60%	7%
Comparing the amounts spent in May	80 u		20 u	100 u

Amount that Pierre saved in percent
= 100% - 60% - 10%
= 30%

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

Total amount that Pierre spent on rental and food in percent
= 60% + 7%
= 67%

100% → 8000

1% → 8000 ÷ 100 = 80

67% → 67 x  80 = 5360

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

80 u = 67% 

80 u = 5360

1 u = 5360 ÷ 80 = 67

Amount that Pierre gave to Zara in May
= 100 u
= 100 x 67
= $6700

Amount that Zara received less from Pierre from April to May
= 8000 - 6700
= $1300

Percentage that the sum given to Zara was reduced by from April to May
= ¹³⁰⁰₈₀₀₀ x 100%
= 16.25%

Answer(s): 16.25%