A. 1/100 * x = 7
x = 7 * 100/1
x = 700
b. 50/100 * x = 33
x = 33 * 100/50
x = 66
c. 3/100 * 100 = 3
d. x/100 * 200 = 6
2x = 6
x = 3
e. 15/100 * 40 = 6
Maximize
subject to 



That's clearly maximum when the squared term is zero, so



Answer: a=12, b=24, max 288
10 and12 is the correct answer