In September, Wesley gave his wife, Sabrina, $10000 for household expenditure. Sabrina spent 60% of the sum on rental, 10% on food and saved the rest. In October, Wesley reduced the sum he gave to Sabrina. Sabrina spent the same amount on rental and reduced the amount she spent on food by 20%. She saved the remaining 20% of the sum given to her in October. By what percentage was the sum given to Sabrina reduced by?

	Rental	Food	Savings	Total
Before	60%	10%	30%	$10000
Change		- 2%	- ?	- ?
After	60%	8%
Comparing the amounts spent in October	80 u		20 u	100 u

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

Amount that Wesley reduced on food in percent
= 20% x 10%
= ²⁰₁₀₀ x 10
= 2%

Total amount that Wesley spent on rental and food in percent
= 60% + 8%
= 68%

100% → 10000

1% → 10000 ÷ 100 = 100

68% → 68 x  100 = 6800

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

80 u = 68% 

80 u = 6800

1 u = 6800 ÷ 80 = 85

Amount that Wesley gave to Sabrina in October
= 100 u
= 100 x 85
= $8500

Amount that Sabrina received less from Wesley from September to October
= 10000 - 8500
= $1500

Percentage that the sum given to Sabrina was reduced by from September to October
= ¹⁵⁰⁰₁₀₀₀₀ x 100%
= 15%

Answer(s): 15%