at the grocery store, you can purchase loose lemons at 2 for $0.99. You can also buy a bag of 6 lemons for $2.50. Which is a better buy

All you have to do is multiply the .99 buy 3, if it equals less than $2.50, which it doesn't then it is the better deal.

Divide 2.50/6 = .42 each lemon in bag, while 2 for .99 would be .495 for each lemon