Question

2. (a) In how many ways can 5 blue balls, 4 white balls and the rest 6 dierent colour balls be arranged in a
row?
(b) A company has 10 software engineers and 6 civil engineers. In how many ways can a committee of 4
engineers be formed from them such that the committee must contain exactly 1 civil engineer?

Answer 1

a) 5 b, 4w, 6d

total 15 balls

no. of ways in which the balls can be arranged in a row = 15! / (5!×4!)

b) 10 s, 6c

committee 4 s and 1c

= 10c4× 6c1

= 10×9×8×7×6/4×3×2

=1260