Question 971848
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There are 2 pints of blue and 2 pints of yellow in the bucket.
To be 80% yellow, the new color will be (100%-80%=) 20% blue.
2 pints is 20% of (2 pints/0.20=) 10 pints. 
With 4 pints in the bucket, to make 10 pints you should add 
(10 pints-4 pints=) 6 more pints of yellow paint.
ANSWER: You should add 6 pints of yellow to the 4 pints of green in the bucket to make the new color that is 80% yellow.