Question

Hershel had 100 baseball cards that he labeled from 1-100. He started with number

one and marked every 5th card with an X, every 7th card with an O and every 10th
card with a V. What number card will be the first to have all 3 marks (XOV)?

Answer 1

I think it is 70.

Explanation:

I think that is the Lowest common Multiple of 5, 7 and 10:

10 = 2*5

7 = 7

5 = 5

So the LCM is 2 * 5 * 7 = 70.

Answer 2

Hey there!

This question is basically asking for the least common multiple, or LCM of the three numbers.

If it is a multiple of 10, it has to be a multiple of 5. Thus, the only thing we need to do now, is find the LCM of 10 and 7, which is 70.

Thus, your answer is 70.

Hope this helps :)