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

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

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

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

Total amount that John 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 John spent on rental and food is repeated. 

75 u = 57% 

75 u = 2850

1 u = 2850 ÷ 75 = 38

Amount that John gave to Emma in December
= 100 u
= 100 x 38
= $3800

Amount that Emma received less from John from November to December
= 5000 - 3800
= $1200

Percentage that the sum given to Emma was reduced by from November to December
= ¹²⁰⁰₅₀₀₀ x 100%
= 24%

Answer(s): 24%