Chase sold 140 milkshakes while working at Frozen Delights. 45% of the milkshakes were mint. The rest were chocolate chip. After Chase sold some more mint milkshakes, the percentage of chocolate chip milkshakes decreased to 50%. How many more mint milkshakes did Chase sell?
140 * .45 = 63
so he sold 63 mint and 77 chocolate
77+x = 1/2 (140+x)