Question

Bingo uses the numbers 1 to 75. If you randomly select a number, What is the probability it will not be a multiple of 7? Express your answer as a fraction.

Answer 1

There are 7 multiples of 10 from 1-75.
There are 75 integers from 1-75.
75 total integers - 7 multiples of 10 = 68 other multiples.
68 others/75 total

=68/75

Answer 2

`\text{The probability that the selected no. is not a multiple of 7 = }(13)/(15)`

Explanation:

Numbers used by Bingo for selection = 1 to 75

Multiples of 7 from 1 to 75 : 7, 14, 21, 28, 35, 42, 49, 56, 63, 70

No. of multiples from 1 to 75 = 10

Total numbers from 1 to 75 = 75

`\text{Probability that the selected no. is multiple of 7 = }(10)/(75)\\\\\text{Probability that the selected no. is not a multiple of 7 = }1-(10)/(75)\\\\=(75-10)/(75)\\\\=(65)/(75)\\\\=(13)/(15)`

`\text{Hence, The probability that the selected no. is not a multiple of 7 = }(13)/(15)`