Question

In a video game, a character needs to shine a light through two spinning wheels that have holes in them.The first wheel makes a complete rotation in 7 seconds.The second wheel makes a complete rotation in 9 seconds.The hole are lined up at 0 seconds.How many seconds will pass before they are lined up again?

Answer 1

63 seconds

they would have to rotate until they became equal so one would rotate 7 times and one would rotate 9 times.