Question

a 4 person dance team will be randomy selected from a pool of dancers consisiting of 5 dancers from town a and 6 dancers from town b. What is the probbality that at least 3 members of the team will be from town b

Answer 1

The probability that at least 3 members of the team will be from town b is 0.3485

Explanation:

We have to find the probability that at least 3 members of the team will be from town b.

At least means 3 or greater than 3.

There are 4 members.

So we have to choose 3 and 4 members from town b which has 6 members

this can be written in the form

6C3 5C1/ 11C4 ( 4 have to be selected out of 11)

= 20*5/330

=0.30

and

6C4 5C0/ 11C4

= 15*1/330

=0.045

P (x≥3) = 6C3 5C1/ 11C4 + 6C4 5C0/ 11C4

= 0.30+0.045

=0.3485 ( rounded)