In March, Luis gave his wife, Fiona, $8000 for household expenditure. Fiona spent 50% of the sum on rental, 30% on food and saved the rest. In April, Luis reduced the sum he gave to Fiona. Fiona 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 April. By what percentage was the sum given to Fiona reduced by?

	Rental	Food	Savings	Total
Before	50%	30%	20%	$8000
Change		- 9%	- ?	- ?
After	50%	21%
Comparing the amounts spent in April	80 u		20 u	100 u

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

Amount that Luis reduced on food in percent
= 30% x 30%
= ³⁰₁₀₀ x 30
= 9%

Total amount that Luis spent on rental and food in percent
= 50% + 21%
= 71%

100% → 8000

1% → 8000 ÷ 100 = 80

71% → 71 x  80 = 5680

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

80 u = 71% 

80 u = 5680

1 u = 5680 ÷ 80 = 71

Amount that Luis gave to Fiona in April
= 100 u
= 100 x 71
= $7100

Amount that Fiona received less from Luis from March to April
= 8000 - 7100
= $900

Percentage that the sum given to Fiona was reduced by from March to April
= ⁹⁰⁰₈₀₀₀ x 100%
= 11.25%

Answer(s): 11.25%