Question

Nikki noticed that is she stacked her dollar bills in stacks of 6 she had 3 left over, stacks of 8, 7 left over, and stacks of 4, 4 left over. If she knows she has less than 100 dollars, how many bills left if she had stacks of 7??

Answer 1

I think you have a typo
If she stacks them in 4's, she can't have 4 left over.

After you find your typo, do the following

numbers which when divided by 6 leave a remainder of 3 are:
3 9 15 21 27 33 39 45 ....
numbers which when divided by 8 leave a remainder of 7 are:
7 15 23 31 39 47 55 ..

do the same for the case where I think you have a typo.

now look for a number or numbers found in all three rows.

then divide that number by 7 and take the remainder.