ACT Math · Probability and counting
A spinner has 8 equal sections numbered 1 through 8. What is the probability that a spin lands on a multiple of 3?
A spinner has 8 equal sections numbered 1 through 8. What is the probability that a spin lands on a multiple of 3?
Answer and explanation
Answer: B: 1/4
The multiples of from to are and , so there are favorable sections out of equally likely sections. The probability is , choice B. Choice A () counts only one favorable section. Choice C () counts three, perhaps by including or by counting , neither of which is on the spinner. Choice D () is the probability of an even number or of an odd number, not of a multiple of . List the favorable outcomes explicitly to avoid miscounting.
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