Take any one of the four numbers from 1 to 4 as the numerator, and take any one of the three numbers from 2 to 4 as the denominator to form a fraction. What is the probability of a fraction with Coprime numerator and denominator?

Take any one of the four numbers from 1 to 4 as the numerator, and take any one of the three numbers from 2 to 4 as the denominator to form a fraction. What is the probability of a fraction with Coprime numerator and denominator?

The fractions of Coprime of molecular denominator are: 1 / 2, 1 / 3, 2 / 3, 1 / 4, 3 / 4
There are: C4 (1) * C3 (1) = 12
The probability of the fraction with Coprime of numerator and denominator is 5 / 12