Question

An archived questions was, "One serving of a particular food contains 16g of carbohydrates, 2g of protein, and 10 g of fats. Approximately how many calories does it contain?" The archived answer was 300 calories. 

How did you get this answer? Shouldn't it be 162?
(9 cal * 10g fat) + (4 cal * 16g carb) + (4cal * 2g protein)

Answer 1

Your answer of 162 is correct. The answer at https://brainly.com/question/3761647 does not show any work or justification for the given answer. And since the normally allowed calories per gram for carbs and protein is 4 and fats is 9, your answer is correct and justifiable. Mind, the actual values using a bomb calorimeter are higher and the difference is attributed to the energy the body expends in digesting the food.

Answer 2

From the information provided, the correct answer should indeed be 162 calories. Your assumptions of 9 calories per gram of fat, 4 calories per gram of carbohydrates, and 4 calories per gram of protein are all correct, and there does not appear to be any error in your math. As you showed, (9 * 10) + (4 * 16) + (4 * 2) = 90 + 64 + 8 = 162. For the typical basic calculation of the amount of calories in a given food, these assumptions are suitable.