In February, Seth gave his wife, Lucy, $6000 for household expenditure. Lucy spent 60% of the sum on rental, 30% on food and saved the rest. In March, Seth reduced the sum he gave to Lucy. Lucy spent the same amount on rental and reduced the amount she spent on food by 30%. She saved the remaining 10% of the sum given to her in March. By what percentage was the sum given to Lucy reduced by?

	Rental	Food	Savings	Total
Before	60%	30%	10%	$6000
Change		- 9%	- ?	- ?
After	60%	21%
Comparing the amounts spent in March	90 u		10 u	100 u

Amount that Seth saved in percent
= 100% - 60% - 30%
= 10%

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

Total amount that Seth spent on rental and food in percent
= 60% + 21%
= 81%

100% → 6000

1% → 6000 ÷ 100 = 60

81% → 81 x  60 = 4860

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

90 u = 81% 

90 u = 4860

1 u = 4860 ÷ 90 = 54

Amount that Seth gave to Lucy in March
= 100 u
= 100 x 54
= $5400

Amount that Lucy received less from Seth from February to March
= 6000 - 5400
= $600

Percentage that the sum given to Lucy was reduced by from February to March
= ⁶⁰⁰₆₀₀₀ x 100%
= 10%

Answer(s): 10%