A 12 oz serving of Pepsi has 41 g of sugar and 150 calories.
A teaspoon of sugar is about 4.2g so it works out at 9.75 teaspoons.
If you work it back from the calories 150 calories divided by 15 (the number of calories in a teaspoon of sugar) gives you 10 teaspoons of sugar.
Either way that's a lot of sugar!!