The number of calories in a piece of pie is 20 less than 3 times the number of calories in a scoop of ice cream. The pie and ice cream together have 500 calories. How many calories are in each?

1 Answer
Jun 20, 2018

The piece of pie has 370 calories while the scoop of ice cream has 130 calories.

Explanation:

Let C_p represent the calories in the piece of pie,
and C_(ic) represent the calories in the scoop of ice cream

From the problem: The calories of the pie is equal to 3 times the calories of the icecream, minus 20.
C_p = 3C_(ic) - 20

Also from the problem, the calories of both added together is 500:
C_p + C_(ic) = 500
C_p = 500 - C_(ic)

The first and last equation are equal (=C_p)
3C_(ic) - 20 = 500 - C_(ic)
4C_(ic) = 520

C_(ic) = 520/4 = 130

Then, we can use this value in any of the equations above to solve for C_p:
C_p = 3C_(ic) - 20
C_p = 3*130 - 20
C_p = 370

So, the piece of pie has 370 calories while the scoop of ice cream has 130 calories.