When x=12, y=8. Find x when y=12

x : y is equal to 12 : 8. These can be reduced or cancelled down to 3 : 2 in the same proportions. Therefore, when y is 12, you have to multiply the smallest value y can be by 6, and must do the same to the smallest x value to retain the proportions. x = 18 when y = 12.