First, we have to know how many prime numbers are:
Prime numbers are numbers that have only 2 factors :1 and themselves.
Prime numbers: 1,3 , 5, 7, 11, 13
So, there area 6 prime numbers out of 8 numbers.
Probability that a single spin lands on a prime number = 6/8 = 0.75
Prediction for 240 spins : 240 x 0.75 = 180 times