In August, Ivan gave his wife, Gwen, $7000 for household expenditure. Gwen spent 50% of the sum on rental, 20% on food and saved the rest. In September, Ivan reduced the sum he gave to Gwen. Gwen spent the same amount on rental and reduced the amount she spent on food by 30%. She saved the remaining 20% of the sum given to her in September. By what percentage was the sum given to Gwen reduced by?

	Rental	Food	Savings	Total
Before	50%	20%	30%	$7000
Change		- 6%	- ?	- ?
After	50%	14%
Comparing the amounts spent in September	80 u		20 u	100 u

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

Amount that Ivan reduced on food in percent
= 30% x 20%
= ³⁰₁₀₀ x 20
= 6%

Total amount that Ivan spent on rental and food in percent
= 50% + 14%
= 64%

100% → 7000

1% → 7000 ÷ 100 = 70

64% → 64 x  70 = 4480

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

80 u = 64% 

80 u = 4480

1 u = 4480 ÷ 80 = 56

Amount that Ivan gave to Gwen in September
= 100 u
= 100 x 56
= $5600

Amount that Gwen received less from Ivan from August to September
= 7000 - 5600
= $1400

Percentage that the sum given to Gwen was reduced by from August to September
= ¹⁴⁰⁰₇₀₀₀ x 100%
= 20%

Answer(s): 20%