Word Problem

Question

Two packets of apples and one packet of brownies contain 700 calories in all. One packet of apples and four packets of brownies contain 1400 calories in all. Find the caloric content of one packet of each food.

Answer 1

a = apples

b = brownies

 

2a + b = 700

a + 4b = 1400

 

b = 700 - 2a  from the first 

a + 4(700 - 2a) = 1400  substituting into second

a + 2800 - 8a = 1400

-7a + 2800 = 1400

1400 = 7a

200 = a

 

The apples have 200 calories and the brownies have 300 calories.