Question: Mo is buying valentine's day cards for the class. There are 30 students and he wants to give a Valentine to 60% of them. They cost $2 each. If he has $40, what percentage of his money will he spend on Valentine? Think carefully first, then make a decision:
He needs 18 valentine's cards because 30 x .6 = 18. He will spend $36 on these because 18 x 2 = 36. The proportion of his income spent is .9 because 36 / 40 = .9. This is 90% of his income because .9 x 100 = 90. So the answer is 90.