An integer is randomly selected between 1 and 50 inclusively

An integer is randomly selected between 1 and 50, inclusively. Find the probability that the number is not divisible by 7.

Solution

We have 7 , 14 , 21 , 28 , 35 , 42 and 49 that are divisible by 7

Between 1 and 50 inclusive, we have 50 numbers in all

So, out of these, 7 are divisible by 7

So, 50 - 7 --> 43 are not divisible by 7

So, P(num not div by 7) = 43 / 50 = 0.86 --> ANSWER