In a group of 750 people, at least 2 have the same first and last initials. Explain why this is true.
When you think about it, you have 26 options for a first initial, and 26 for a last initial. You can get (26*26) different pairs of initials without any repeating pairs.
26*26=676, so you could say that in a group of 677 people, minimally 2 people would have the same first and last initial.