What is the probability that a randomly selected three-digit number is divisible by 5? Express answer as a common fraction.

Since every fifth number is divisible by 5, divide by 5.

1/5 = .20

To find the probability that a randomly selected three-digit number is divisible by 5, we first need to determine how many three-digit numbers are divisible by 5 and then divide that by the total number of three-digit numbers.

The first step is to find the range of three-digit numbers. The smallest three-digit number is 100, and the largest three-digit number is 999.

To determine how many three-digit numbers are divisible by 5, we need to figure out how many multiples of 5 fall within this range. The smallest multiple of 5 within this range is 100 (5 times 20), and the largest multiple of 5 is 995 (5 times 199).

To find out how many numbers are between 100 and 995 (inclusive) that are divisible by 5, we can subtract 100 from 995 and then divide the result by 5 (as there is one multiple of 5 every five numbers).

(995 - 100) / 5 = 895 / 5 = 179

So, there are 179 three-digit numbers that are divisible by 5.

The total number of three-digit numbers is found by subtracting the smallest three-digit number from the largest and then adding 1 (to include both endpoints).

999 - 100 + 1 = 900

So, there are 900 three-digit numbers in total.

Therefore, the probability of randomly selecting a three-digit number that is divisible by 5 is:

179 / 900

This fraction cannot be simplified any further, so the answer is:

179 / 900