In August, Will gave his wife, Nora, $4500 for household expenditure. Nora spent 50% of the sum on rental, 20% on food and saved the rest. In September, Will reduced the sum he gave to Nora. Nora 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 Nora reduced by?

	Rental	Food	Savings	Total
Before	50%	20%	30%	$4500
Change		- 6%	- ?	- ?
After	50%	14%
Comparing the amounts spent in September	80 u		20 u	100 u

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

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

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

100% → 4500

1% → 4500 ÷ 100 = 45

64% → 64 x  45 = 2880

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

80 u = 64% 

80 u = 2880

1 u = 2880 ÷ 80 = 36

Amount that Will gave to Nora in September
= 100 u
= 100 x 36
= $3600

Amount that Nora received less from Will from August to September
= 4500 - 3600
= $900

Percentage that the sum given to Nora was reduced by from August to September
= ⁹⁰⁰₄₅₀₀ x 100%
= 20%

Answer(s): 20%