Garrett was arranging marbles on his bedroom floor one rainy day when he was really bored. He arranged all of his marbles into piles of
three, but there were two marbles left over. So he started over again
and put all of his marbles into piles of four, but again there were two
left over. He started getting frustrated, so he put all of his marbles into
piles of five, but again there were two left over. Then he tried piles
of six, but again there were two left over. He gave up in complete
frustration and put all of his marbles back in his closet. If Garrett has
more than 6 but fewer than 100 marbles, how many marbles does
he have? What would have happened if Garrett had arranged them
into piles of two?