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Find the probability that a number selected at random from 21 to 34 is a multipl...

Question

Find the probability that a number selected at random from 21 to 34 is a multiple of 3

Options

A) $$\frac{3}{11}$$

B) $$\frac{2}{9}$$

C) $$\frac{5}{14}$$

D) $$\frac{5}{13}$$

Explanation:

S = {21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34}
n(S) = 14
multiples of 3 = {21, 24, 27, 30, 33}
n(multiples of 3) = 5
Prob( picking a multiple of 3) = 5/14

Dicussion (1)

• S = {21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34}
n(S) = 14
multiples of 3 = {21, 24, 27, 30, 33}
n(multiples of 3) = 5
Prob( picking a multiple of 3) = 5/14