Emily is playing a board game that has a spinner divided into equal sections numbered 1 to 18.

Question

The probability of the spinner landing on an even number or a multiple of 3 is 1/6, 1/3, 1/2, 2/3, or 5/6. The probability of the spinner landing on an odd number or a number between 4 and 15 (both numbers excluded) is 13/18, 1/3, 7/9, 2/3, or 5/6.

Answer 1

Pr(Even) = 1/2, Pr(multiple of 3) = 1/3

Pr(Even or 3) = 1/2 + 1/3 - Pr(6,12, or 18)

Pr(Even or 3 = 5/6 - 3/18 = 12/18= 2/3

Pr(Odd) = 1/2

Pr(5 through 14) = 10/18 = 5/9

Pr(Odd and 5 through 14) = Pr(5,7,9,11,13) = 5/18

Pr(Odd or 5 through 14) = 1/2 + 5/9 - 5/18 = 14/18 = 7/9