SOLUTION: The number of calories in a piece of pie is 20 less than three times the number of calories in a scoop of ice cream. The pie and ice cream together have 500 calories. How many calo

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The number of calories in a piece of pie is 20 less than three times the number of calories in a scoop of ice cream. The pie and ice cream together have 500 calories. How many calo      Log On


   

Question 261101: The number of calories in a piece of pie is 20 less than three 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?
I don't understand how to put the equation together.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The number of calories in a piece of pie is 20 less than three 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?
-------------
Equations:
Quantity Equation: p + i = 500
Quantity Equation: p = 3i -20
-------------------------------------
Substitute for "p" and solve for "i":
3i-20 + i = 500
4i = 520
i = 130 (# of calories in ice cream)
---------------------------------
Since p+i = 500, p = 500-130 = 370 (# of calories in a piece of pie)
=======================================================================
Cheers,
Stan H.