Question

According to government data, the probability that a woman between the ages of 25 and 29 was never married is 40%. in a random survey of 10 women in this age group, what is the probability that two or fewer were never married

Answer 1

The probability of finding 2 never married
10c2*0.4^2*0.6^8=
the probability of finding 1 never married
10C1*0.4*0.6^9=
the probability of finding 0 never married
10C0*0.6^10=

the answer is all the above answers added together.
think you can do the rest of the calculation by yourself. :)

btw nCr=n!/(n-r)!r!
good luck