As of June 2015, 81.4% of patients were waiting on a kidney, 11.7% were waiting on a

Question:

As of June 2015, 81.4% of patients were waiting on a kidney, 11.7% were waiting on a liver, and 3.1% were waiting on a heart. Choose 6 patients on the transplant waiting list at random in 2015. Find the probability that
a. All were waiting for a kidney.
b. None were waiting for a kidney.
c. At least 1 was waiting for a kidney