Problem:
Jeff rotates spinners and and adds the resulting numbers. What is the probability that his sum is an odd number?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Because the sum of a number from spinner and a number from spinner is always odd, the sum of the numbers on the three spinners will be odd exactly when the number from spinner is even. Because is the only even number on spinner , the probability of getting an odd sum is .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions