In August, Tom gave his wife, Nora, $8000 for household expenditure. Nora spent 50% of the sum on rental, 10% on food and saved the rest. In September, Tom reduced the sum he gave to Nora. Nora 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 September. By what percentage was the sum given to Nora reduced by?

	Rental	Food	Savings	Total
Before	50%	10%	40%	$8000
Change		- 2%	- ?	- ?
After	50%	8%
Comparing the amounts spent in September	80 u		20 u	100 u

Amount that Tom saved in percent
= 100% - 50% - 10%
= 40%

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

Total amount that Tom spent on rental and food in percent
= 50% + 8%
= 58%

100% → 8000

1% → 8000 ÷ 100 = 80

58% → 58 x  80 = 4640

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

80 u = 58% 

80 u = 4640

1 u = 4640 ÷ 80 = 58

Amount that Tom gave to Nora in September
= 100 u
= 100 x 58
= $5800

Amount that Nora received less from Tom from August to September
= 8000 - 5800
= $2200

Percentage that the sum given to Nora was reduced by from August to September
= ²²⁰⁰₈₀₀₀ x 100%
= 27.5%

Answer(s): 27.5%