In February, Oscar gave his wife, Nora, $5000 for household expenditure. Nora spent 50% of the sum on rental, 10% on food and saved the rest. In March, Oscar reduced the sum he gave to Nora. Nora 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 March. By what percentage was the sum given to Nora reduced by?

	Rental	Food	Savings	Total
Before	50%	10%	40%	$5000
Change		- 3%	- ?	- ?
After	50%	7%
Comparing the amounts spent in March	75 u		25 u	100 u

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

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

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

100% → 5000

1% → 5000 ÷ 100 = 50

57% → 57 x  50 = 2850

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

75 u = 57% 

75 u = 2850

1 u = 2850 ÷ 75 = 38

Amount that Oscar gave to Nora in March
= 100 u
= 100 x 38
= $3800

Amount that Nora received less from Oscar from February to March
= 5000 - 3800
= $1200

Percentage that the sum given to Nora was reduced by from February to March
= ¹²⁰⁰₅₀₀₀ x 100%
= 24%

Answer(s): 24%