In March, Justin gave his wife, Diana, $8000 for household expenditure. Diana spent 70% of the sum on rental, 10% on food and saved the rest. In April, Justin reduced the sum he gave to Diana. Diana 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 April. By what percentage was the sum given to Diana reduced by?

	Rental	Food	Savings	Total
Before	70%	10%	20%	$8000
Change		- 3%	- ?	- ?
After	70%	7%
Comparing the amounts spent in April	80 u		20 u	100 u

Amount that Justin saved in percent
= 100% - 70% - 10%
= 20%

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

Total amount that Justin spent on rental and food in percent
= 70% + 7%
= 77%

100% → 8000

1% → 8000 ÷ 100 = 80

77% → 77 x  80 = 6160

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

80 u = 77% 

80 u = 6160

1 u = 6160 ÷ 80 = 77

Amount that Justin gave to Diana in April
= 100 u
= 100 x 77
= $7700

Amount that Diana received less from Justin from March to April
= 8000 - 7700
= $300

Percentage that the sum given to Diana was reduced by from March to April
= ³⁰⁰₈₀₀₀ x 100%
= 3.75%

Answer(s): 3.75%