<span>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.</span>