1. A box contains a number of items, among them exactly 10 hats, 3 books, and 7 statues. The remaining 1/3 of the items are all blue T-shirts. What percent of the items in the box are books?

Answer 1

10 + 3 + 7 + 1/3x = x

20 = 2/3x

20/(2/3) = x

20 * (3/2) = x

60/2 = 30 = x

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

3/30 = 0.1 = 10%