You are running a fruit cart and need to stock up on supplies. The cost of an apple cup is $0.75 cents. The cost of an orange cup is $0.50 cents and the cost for a banana cup is $0.85 cents. You only...

You are running a fruit cart and need to stock up on supplies. The cost of an apple cup is $0.75 cents. The cost of an orange cup is $0.50 cents and the cost for a banana cup is $0.85 cents. You only have $400 dollars and have to purchase 700 fruit cups. You would prefer to buy more apple cups then the rest because they are the best seller and banana cups don't sell well at all so you don't need many of those.

My question is how would you even begin to answer a problem like this? Where do you start? I've been making random guesses and I can't get the numbers to match up right. Every combination that I try gets me to the 700 fruit cups but I keep going over the budget of 400 dollars. Help please :)?