Step 1
- Consider that drilling in a location is a trial.
- Probability of success in each trial is p=0.25,
- Probability of failure is q=1-p=1-0.25=0.75
Step 2
a) Let random variable X represent the number of success among 10 drills.
Because trials are independent, X has binomial distribution with parameters n=10 and p=0.25.
Probability mass function of X is
Lets calculate the probability the driller drills at at 10 locations and has 1 success.
=0.1877
Step 3
b) Let random variable X represent the number of drills required to get first success.
Now, lets find the probability that the driller prospects for bankruptcy, in other words, that there are no successes in 10 trials.
=0.05631