Question

Slips of paper numbered 1–20 are folded and placed into a hat, and then a slip of paper is drawn at random. What is the probability the slip drawn has a number which is a multiple of 4 or 5?

Answer 1

To start, we need to figure which numbers, between 1 and 20 are divisible by 4 and 5. Those divisible by 4 are 4, 8, 12, 16 and 20. Those divisible by 5 are 5, 10, 15 and 20. There are a total of 8 unique number divisible by 4 or 5. Therefore, the probability of picking a number divisible by 4 or 5 is 8/20 or 2/5 or 40%.

Explanation: