We solved the mystery of the best size fries to order at a fast food restaurant. Now, we are going to tackle the soda fountain. That's right Theorists, we are busting out the math to see which of your favorite fast food hang outs is tricking you into paying for a larger drink size while still only serving you the SAME amount of drink! Today we are putting McDonalds, Taco Bell, Burger Kings, Wendy's and KFC into a head to head battle to see which place you should go to get the best bang for your buck in terms of drink size. Which place is feeling generous and which is a major scam? It's time to pour ourselves a large cup of TRUTH!