Solution:We are given:p=(8)/(10)=0.8q=1-p=1-0.8=0.2a) We have to find:P(x=3)Using the Geometric distribution, we have:P(x=3)=0.8 xx0.2^(3-1)=0.032b) We have to find:P(x >= 3)Using the complementary law of probability, we have:P(x >= 3)=1-P(x <= 2)                    =1-(P(x=1)+P(x=2))                    =1-(0.8 xx0.2^(1-1)+0.8 xx0.2^(2-1))                    =1-(0.8+0.16)                 & ... See the full answer