24.2k views
3 votes
How many numbers between 1 and 100 (inclusive) are divisible by 5 or 8?

1 Answer

2 votes

Final answer:

Numbers divisible by 5: There are 20 numbers (5, 10, 15, ..., 100).

Numbers divisible by 8: There are 12 numbers (8, 16, 24, ..., 96).

There are 30 numbers between 1 and 100 that are divisible by 5 or 8.

Step-by-step explanation:

To calculate how many numbers between 1 and 100 are divisible by 5 or 8, we use the principle of inclusion-exclusion. First, we find how many numbers are divisible by 5, then how many are divisible by 8, and then we subtract the numbers that are divisible by both 5 and 8 since those are counted twice.

Numbers divisible by 5: There are 20 numbers (5, 10, 15, ..., 100).
Numbers divisible by 8: There are 12 numbers (8, 16, 24, ..., 96).

To find the numbers divisible by both 5 and 8 (which is the same as being divisible by 40), there are 2 such numbers (40 and 80).

Using the inclusion-exclusion principle, we get:

Total = Numbers divisible by 5 + Numbers divisible by 8 - Numbers divisible by both 5 and 8

Total = 20 + 12 - 2 = 30.

Therefore, there are 30 numbers between 1 and 100 that are divisible by 5 or 8.

User Phoibos
by
8.2k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories