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 hard. Detailed solution:
90
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.

.

The answer is 90