Melanie has a 4 gallon mixture of “homemade” orange paint mixed with red andyellow paint at a 3:7 ratio. However, the orange is a little bit too red to her liking,and she realized that she actually wanted a 2:5 ratio instead. Fortunately, she hasa lot of yellow paint. How many gallons of yellow paint should Melanie add to themixture to achieve the 2:5 ratio?
+37146 7 out of (3+7) is yellow 7/10
Her new mixture will be 5 out of 7 or 5/7 yellow
7/10 ( 4 gal) + y gallons = 5/7 ( 4+y)
28/10
28/10 + y = 20/7 + 5/7 y
196/70 + y = 200/70 + 50/70 y
-4/70 = -20/70 y
y = 4/20 = 1/5 gallon
