A geologist has collected 10 specimens of basaltic rock and 10 specimens of granite. * The geologist instructs a laboratory assistant to randomly select 15 of the specimens for analysis
a) What is the probability function of the number of granite specimens selected for analysis?
b) What is the probability that all specimens of one of the two types of rock are selected for analysis?
c) What is the probability that the number of granite specimens selected for analysis is within 1 standard deviation of its mean value?