You are served dessert at a restaurant. you want to know what % of the calories in the dessert are from fat. the menu states that there are 10 grams of fat, 30 grams of carbohydrates and 4 grams of protein in the dessert. you know that the number of calories per gram is roughly the same for both protein and carbohydrates. what percentage of calories comes from fat for your dessert?

39.82 %

Explanation:

Proteins and carbohydrates provide 4 calories per gram. On the other hand, fats provide 9 calories.

We can first calculate the calories of protein + carbohydrates:

       (30g + 4g) x 4 = 136 calories

And we must calculate the calories provided by fat:

        10g x 9 = 90 calories

Now to get the percentage we must see how many calories the dessert has in total:

          136 + 90 = 226 cal

This represents 100% of calories. And now we need to find out how much 90 calories are from the total.

           226 cal > 100%

             90 cal > X

       (90 x 100) / 226 = 39.82 %