A particular kind of Spanish orange is completely fat free. If one of the oranges has 40 Calories total and a test shows that it contains 1gram of protein, how many grams of carbohydrates does it have

                      9 grams of Carbohydrates

Explanation:

                     The energies contained by each class of these compounds are as;

(i)  Fats:

            1 grams of Fat contains 9 Calories

(ii)  Proteins:

            1 grams of Proteins have 4 Calories

(iii)  Carbohydrates:

            1 grams of Carbohydrates contains 4 Calories

(iv)  Vitamins and Minerals:

            Vitamins and Minerals have no Calories

Solution:

As 1 gram of Protein Contains 4 Calories so, we will subtract 4 Calories from the total Calories contained by the Juice as,

Calories by Carbohydrates  =  Total Calories - Calories by Protein

Calories by Carbohydrates  =  40 - 4

Calories by Carbohydrates  =  36 Calories.

Hence,

As,

           4 Calories were contained by  =  1 gram of Carbohydrate

So,

       36 Calories will be contained by  =  X grams of Carbohydrates

Solving for X,

                      X =  36 Calories × 1 gram / 4 Calories

                       X  =  9 grams of Carbohydrates