The probability of obtaining a prime number when you spin the spinner once is 33.3%.
How to calculate the probability?
The probability of obtaining a prime number when you spin the spinner once is calculated as follows;
Probability = possible outcome / total outcome
The given numbers in the spinner;
6, 7, 8
The only prime number among the given numbers is 7.
The probability of obtaining a prime number is calculated as;
P(prime) = possible outcome / total outcome
P(prime) = 1 / 3
P(prime) = 0.333
P(prime) = 0.333 x 100%
P(prime) = 33.3%