Question

An integer is chosen at random between 1 and 100. Find the probability that it is divisible by 8. Please give the correct answer as per the board answer key as there is a lot of confusion with the total number of outcomes being 100 or 98.
Keep in mind the photos I have sent.

Answer 1

1) We can find total no. of integer between 1 and 100 that are divisible by 8 by using A.P.
So, Series = 8, 16, 24......96a = 8an = 96d = 8
an = a + (n - 1)d
=> 96 = 8 + (n - 1)8
=> 88/8 = n - 1
=> n = 12
So, possible outcome = 12Total no. of outcome = 98p(getting a no. divisible by 8) = 12/98= 6/49
2) Total no. that are not divisible by 8 between 1 and 100 = 98 - 12 = 86
Possible outcome = 86Total no. of outcome = 98
P(getting no. not divisible by 8) = 86/98
= 43/49
Hope this helps....:)