## Simple Fractions

#### Problem

A fraction whose numerator (top number) is less than its denominator (bottom number) is called a simple fraction.

1 9 | 2 9 | 4 9 | 5 9 | 7 9 | 8 9 |

There are six simple fractions involving ninths that cannot be cancelled down. How many simple fractions with a denominator equal to 24 cannot be cancelled down?

Problem ID: 72 (Apr 2002) Difficulty: 1 Star