Solution:
p=35,q=25,n=5,P(x=r)=nCr(p)r(q)n-rP(X≥3)=P(X=3)+P(X=4)+P(X=5)=5C3(35)3(25)2+5C4(35)4(25)+5C5(35)5
=3355(40+30+9)=27×793215=21333215=0.66
A and B play a game in which their chances of winning are in the ratio 3:2. The probability of A winning atleast 3 games out of 5 games is
p=35,q=25,n=5,P(x=r)=nCr(p)r(q)n-rP(X≥3)=P(X=3)+P(X=4)+P(X=5)=5C3(35)3(25)2+5C4(35)4(25)+5C5(35)5
=3355(40+30+9)=27×793215=21333215=0.66