Question

Of five letters (A, B, C, D, and E), two letters are to be selected at random. How many possible selections are there?

Answer 1

`10`

Explanation:

Given: 5 letters (A, B, C, D, E), select two at random. How many possible selections are there?

`""_5C_2 = (5!)/((5-2)! 2!) = (5 xx 4 xx cancel(3!)) / (cancel(3!) xx2 xx 1) = 20/2 = 10`