In July, Wesley gave his wife, Kathy, $8000 for household expenditure. Kathy spent 60% of the sum on rental, 10% on food and saved the rest. In August, Wesley reduced the sum he gave to Kathy. Kathy 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 August. By what percentage was the sum given to Kathy reduced by?

	Rental	Food	Savings	Total
Before	60%	10%	30%	$8000
Change		- 1%	- ?	- ?
After	60%	9%
Comparing the amounts spent in August	80 u		20 u	100 u

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

Amount that Wesley reduced on food in percent
= 10% x 10%
= ¹⁰₁₀₀ x 10
= 1%

Total amount that Wesley spent on rental and food in percent
= 60% + 9%
= 69%

100% → 8000

1% → 8000 ÷ 100 = 80

69% → 69 x  80 = 5520

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

80 u = 69% 

80 u = 5520

1 u = 5520 ÷ 80 = 69

Amount that Wesley gave to Kathy in August
= 100 u
= 100 x 69
= $6900

Amount that Kathy received less from Wesley from July to August
= 8000 - 6900
= $1100

Percentage that the sum given to Kathy was reduced by from July to August
= ¹¹⁰⁰₈₀₀₀ x 100%
= 13.75%

Answer(s): 13.75%