You need to do 20 divide by 21 to get a decimal. Then if you multiply the decimal by hundred you should get the percentage.
Using the distributive property an equivalent expression would be 9z-54
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
