Question

The ways of selecting 4 letters from the word `examination' is

Answer 1

Answer:

Number of ways selecting 2 alike,2 alike = 3c2 = 3 ways. 2) Number of ways selecting 2 alike,2 different = 3c1 x 7c2 = 3 x 21 = 63 ways. 3) Numkber of ways selecting all 4 different = 8c4 = 70 ways. ∴ Total number of combinations = 3 + 63 + 70 = 136 ways.