Among the fractions 1/2, 1/3, 1/4, 1/5, 1/6, 1/7, 1/8, 1/9, 1/10, how many have a terminating decimal expansion?

Question

Accepted Answer

5. Terminating: 1/2, 1/4, 1/5, 1/8, 1/10 (denominators with only 2 and 5). That is 5. Non-terminating: 1/3, 1/6, 1/7, 1/9.

Among the fractions $\frac{1}{2}, \frac{1}{3}, \frac{1}{4}, \frac{1}{5}, \frac{1}{6}, \frac{1}{7}, \frac{1}{8}, \frac{1}{9}, \frac{1}{10}$ , how many have a terminating decimal expansion?