Tender bids

Hello,

This is my first post here.
I need help with tender bids.

Company AAA have 5 workers, BBB 7 ...
Part 1 require 2 workers, Part 2 require 4 workers...
Each company have limited number of workers.
Company AAA offer 56 for part 1, 99 for part 2, 102 for part 3...
How can I find winning bids if I want that sum of winning bids is smallest posible, but also considering how many workers are needed.

Thanks