In September, Jenson gave his wife, Pamela, $10000 for household expenditure. Pamela spent 50% of the sum on rental, 20% on food and saved the rest. In October, Jenson reduced the sum he gave to Pamela. Pamela 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 October. By what percentage was the sum given to Pamela reduced by?

	Rental	Food	Savings	Total
Before	50%	20%	30%	$10000
Change		- 2%	- ?	- ?
After	50%	18%
Comparing the amounts spent in October	80 u		20 u	100 u

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

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

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

100% → 10000

1% → 10000 ÷ 100 = 100

68% → 68 x  100 = 6800

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

80 u = 68% 

80 u = 6800

1 u = 6800 ÷ 80 = 85

Amount that Jenson gave to Pamela in October
= 100 u
= 100 x 85
= $8500

Amount that Pamela received less from Jenson from September to October
= 10000 - 8500
= $1500

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

Answer(s): 15%