Question

To complete his degree a part time student needs to do three more subjects. assuming he can only take one subject per semester, and that he passes a subject with probability 0.85 independently of his past results, find the probability that he will need more than 2 but not more than 3 years to graduate?

Answer 1

Here we have the passing probability of find in out the probabiling of more than 2 but not We have to passing subejects more than 3 : If x is have calculate Tondam variable. the we . Here we have passing prob. P20.85 4 at least in 2 solo da bupassings is required so random variable follows binomial list then it's pochf. is Pyle) = se, pranoko na011,2...n र वटा पावित p[2 24 <3] = P(x<37 - P[25x7 = (1-P(x2,3]) - P[2x] = (1- (3 (0.85% Co 1580) (32 (0.85 (0.15)) - 0.002072) I - 0.325125 0.997928-0.325125 P[234 L3] = 0.672803

The probability that he will need more than 2 but not more than 3 years to graduate is 0.672803