Please help me with this problem, I don't understand it pretty well.

The management of bidding of a company understands that the low bid X in certain type of project is a random variable with pdf given for: f (x) = 0.75C for 2C/3 <x <2C where C represents the cost of the project estimated by the management. Fnd the percentage that the management should add to its initial estimation of costs when they should send the bids, if they want to maximize his awaited profit.

Thank you!