Question

A box contains 2 blue caps, 4 red caps, 5 green caps and1 yellow cap. If four caps are picked at random, then the probability that none of them is green, is A. 7 99 7 B. 5 99 5 C. 7 12 7 D. 5 12 5 Select the correct answer from above options

Answer 1

Correct Answer - A Total number of caps = 12 Total result n(S) = 12 C 4 = n ( S ) = 12 ! 4 ! .8 ! = 12 × 11 × 10 × 9 × 8 ! 4 × 3 × 2 × 1 × 8 ! = 5 × 99 n n€ = Out of 7 caps , number of ways to pick 4 caps 7 C 4 = 7 ! 4 ! .3 ! = 7 × 6 × 5 × 4 × 3 ! 4 × 3 × 2 × 1 × 3 ! = 35 7 P ( E ) = n ( E ) n ( S ) = 35 5 × 99 = 7 99 P