In March, Ken gave his wife, Julie, $8000 for household expenditure. Julie spent 50% of the sum on rental, 20% on food and saved the rest. In April, Ken reduced the sum he gave to Julie. Julie spent the same amount on rental and reduced the amount she spent on food by 10%. She saved the remaining 20% of the sum given to her in April. By what percentage was the sum given to Julie reduced by?

	Rental	Food	Savings	Total
Before	50%	20%	30%	$8000
Change		- 2%	- ?	- ?
After	50%	18%
Comparing the amounts spent in April	80 u		20 u	100 u

Amount that Ken saved in percent
= 100% - 50% - 20%
= 30%

Amount that Ken reduced on food in percent
= 10% x 20%
= ¹⁰₁₀₀ x 20
= 2%

Total amount that Ken spent on rental and food in percent
= 50% + 18%
= 68%

100% → 8000

1% → 8000 ÷ 100 = 80

68% → 68 x  80 = 5440

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

80 u = 68% 

80 u = 5440

1 u = 5440 ÷ 80 = 68

Amount that Ken gave to Julie in April
= 100 u
= 100 x 68
= $6800

Amount that Julie received less from Ken from March to April
= 8000 - 6800
= $1200

Percentage that the sum given to Julie was reduced by from March to April
= ¹²⁰⁰₈₀₀₀ x 100%
= 15%

Answer(s): 15%