A special die is made in the shape of an octahedron.

The die has 8 equal faces marked with the numbers 1 to 8.

If the die is thrown once, what is the probability that the face that lands uppermost has a prime number?

Solution:

Let A = probability that the face that lands uppermost has a prime number.

In the pool of {1, 2, 3, 4, 5, 6, 7, 8}, {2, 3, 5, 7} are prime.

P(A) = 4/8 = 1/2

Correct?