Question

if you are picking a number between 1 and 20 what is the probability that you will pick an even number or a multiple of three

Answer 1

3/5

Explanation:

First, identify "successes:"

Even numbers between 1 and 20 are {2, 4, 6, 8, 10, 12, 14, 16, 18, 20}.

Multiples of 3 are {3, 6, 9, 12, 15, 18}

Those unique numbers that constitute "successes" are thus:

{2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 18, 20}. There are 12 such numbers, out of 20.

Thus, "the probability that you will pick an even number or a multiple of three" is 12/20, or 3/5.

Answer 2

multiples of 3 = 3, 6, 9, 12, 15, 18

even number = 2,4,6,8,10,12,14,16,18, 20

altogether = 2, 3, 4, 6, 8, 9 ,10, 12, 14, 15, 16, 18, 20

there fore 13/20