Question 254918
Initially there were 7 liters of blue paint and 10 liters of crimson paint. 
A paint job uses 20% of the blue and 80% of the crimson paint.
(a) What percentage of the total combined amount of paint is used during the job?
Amount Used = 0.20*7 + 0.80*10 = 1.4 + 8 = 9.4 liters
Percent Used: 9.4/(7+10) = 0.5529 = 55.29%
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(b) What percentage of the total combined amount of paint remains after the job is finished?
Ans: 100% - 55.29% = 44.71%
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Cheers,
Stan H.