calories in a cup of sunflower seeds and rasins

Question

Paula mixed 2 cups of sunflower seeds and 3 cups of raisins to make a snack for a hike. She figured that the mixture would provide her with 2900 calories of food energy. Find the number of calories per cup of raisins if it is 400 less than the number of calories per cup of sunflower seeds.

Answer 1

 x = number of calories in a cup of raisins:

x+400= number of calories in a cup of seeds

An equation could be:

Seed cal + raisin cal = 2900 cal

 

2(x+400) + 3(x) = 2900

2x + 800 + 3x = 2900

 

2x + 3x = 2900 - 800

5x = 2100

x = 2100/5

x = 420 calories in a cup of raisins

420 + 400 = 820 calories in a cup of seeds