Imagine you wanted to make sandwiches for you and a friend. It sounds simple, but it already involves some repetitive tasks.

Can you finish the sequence?

press slices 1 and 3 together
press slices 2 and 4 togetherpress slices 1 and 2 together
press slices 3 and 4 together

Complicated, huh? Just imagine you were to make sandwiches for ten or more people!

Are you sure? Doesn't that make one PB sandwich and one J sandwich?