In February, Riordan gave his wife, Opal, $6000 for household expenditure. Opal spent 50% of the sum on rental, 20% on food and saved the rest. In March, Riordan reduced the sum he gave to Opal. Opal 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 March. By what percentage was the sum given to Opal reduced by?

	Rental	Food	Savings	Total
Before	50%	20%	30%	$6000
Change		- 6%	- ?	- ?
After	50%	14%
Comparing the amounts spent in March	80 u		20 u	100 u

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

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

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

100% → 6000

1% → 6000 ÷ 100 = 60

64% → 64 x  60 = 3840

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

80 u = 64% 

80 u = 3840

1 u = 3840 ÷ 80 = 48

Amount that Riordan gave to Opal in March
= 100 u
= 100 x 48
= $4800

Amount that Opal received less from Riordan from February to March
= 6000 - 4800
= $1200

Percentage that the sum given to Opal was reduced by from February to March
= ¹²⁰⁰₆₀₀₀ x 100%
= 20%

Answer(s): 20%