In January, Mark gave his wife, Vanessa, $6000 for household expenditure. Vanessa spent 60% of the sum on rental, 30% on food and saved the rest. In February, Mark reduced the sum he gave to Vanessa. Vanessa 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 February. By what percentage was the sum given to Vanessa reduced by?

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

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

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

Total amount that Mark 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 Mark spent on rental and food is repeated. 

90 u = 81% 

90 u = 4860

1 u = 4860 ÷ 90 = 54

Amount that Mark gave to Vanessa in February
= 100 u
= 100 x 54
= $5400

Amount that Vanessa received less from Mark from January to February
= 6000 - 5400
= $600

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

Answer(s): 10%