In October, Owen gave his wife, Opal, $8000 for household expenditure. Opal spent 60% of the sum on rental, 20% on food and saved the rest. In November, Owen 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 November. By what percentage was the sum given to Opal reduced by?

	Rental	Food	Savings	Total
Before	60%	20%	20%	$8000
Change		- 6%	- ?	- ?
After	60%	14%
Comparing the amounts spent in November	80 u		20 u	100 u

Amount that Owen saved in percent
= 100% - 60% - 20%
= 20%

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

Total amount that Owen spent on rental and food in percent
= 60% + 14%
= 74%

100% → 8000

1% → 8000 ÷ 100 = 80

74% → 74 x  80 = 5920

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

80 u = 74% 

80 u = 5920

1 u = 5920 ÷ 80 = 74

Amount that Owen gave to Opal in November
= 100 u
= 100 x 74
= $7400

Amount that Opal received less from Owen from October to November
= 8000 - 7400
= $600

Percentage that the sum given to Opal was reduced by from October to November
= ⁶⁰⁰₈₀₀₀ x 100%
= 7.5%

Answer(s): 7.5%