Jasper had his marbles out on the floor the other day. His little sister Pearl was putting them in equal piles, or at least trying to. When she tried to put them in two equal piles, she had one marble left over. When she tried to make three equal piles she had two marbles left over. When she tried to make four equal piles, she had three marbles left over. Then she got mad and threw all of the marbles under the piano. Jasper pulled them all out (he found all of them, and he kept his temper) and put them into seven equal piles, with no marbles left over. How many marbles does he have?
Solution
Jasper has a number of marbles that is a multiple of 7: 7, 14, 21, 28, 35, 42, etc. Looks as if he has 35 marbles.