Question

An integer is chosen at random from 1 to 50 inclusive. Find the probability that the chosen integer is divisible by 3. 8/25 3/10 3/50

Answer 1

How many numbers from 1 to 50 are multiples of 3?

3, 6, 9, 12, 15, 18 .......

Let's change the start and end value of the array and find the number of terms

Start at 3 and go all the way to 48 because those are the first and last multiples of 3 in this array.

There is a formula that allows us to quickly find the number of terms

We subtract the first term from the last term and divide by the amount of increase, then we add 1.

(48 - 3) / 3 + 1   =   16 numbers are exactly divisible by 3.

We have 50 numbers and 16 of them divisible by 3

16 / 50  = 8 / 25 probability