1) Everyone at the party shook hands with everyone else exactly once. If there were a total of 21 handshakes, how many people were at the party?
2) Kathy tossed a coin 8 times and got 3 heads and 5 tails. How many different sequences of results could she have gotten?
Thanks! These are a couple problems that have stumped me and need some help on :)
1. We can use the handshakes formula here...n(n-1) / 2 =21 n(n-1)=42, n=7 people at the party.
2. Think of arranging three identical letters with five other identical letters. How many ways are there to do this?