Your company assigned two accident insurance plans

(Plan 1 and Plan 2) among the full-time and part-time staffs. There are 70% of full-time staffs in the company and 60% of staffs had been assigned in Plan 2. Given Plan 1, the probability for full-time staff is 0.75 and the probability for part-time staff is 0.25. The company assigned Plan 2 to part-time staffs with the probability of 0.2.

a. What is the probability of a full-time staff with Plan 1 accident insurance?

b. What is the probability of a part-time staff with Plan 1 or Plan 2?

c. If two staffs were selected, what is the probability of both of them assigned with Plan 1?