Any idea on how to do this? I'm a little confused.

At a lunchron, guests are offered a selection of five different grilled vegetables and four different meats. in how many waya could one choose three vegetables and two meats?

You earn a 12% commission for every car you sell. how much is your commission if you sell a $23,000 car?

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab