Can anyone help me with this prorbability application problem please.

A consulting frim submitted a bid for a large research project. THe firm's manager felt they had a 50-50 chance of getting the porject. The agency to which the bid was to be submitted subsequently requested additional information on the bid. Past experience indicates that for 75% of the successful bids and 40% of the unsuccesful bids the agency requested additional information.

a. What is the prior probability of the bid being successful bids (that is,
prior to the request for information)?

b. What is the conditonal probability of a reuest for additional information
given that the bid will ultimately be sucessful.

c. Compute the posterior probability that the bid would be successful
given a request for additional information?