Question

A pound of apples and a pound of oranges cost $5.00.

A pound of apples and a pound of grapes cost $5.50.
A pound of oranges and a pound of grapes cost $6.00.
What is the total cost of a pound of apples, a pound of grapes and a pound of oranges in dollars?

Answer 1

Let

a ----> the cost of one pound of apples

o ---> the cost of one pound of oranges

g ---> the cost of one pound of grape

so

we have

a+o=5 ---> equation 1

a+g=5.50 ----> equation 2

o+g=6 ----> equation 3

step 1

subtract 2 from equation 3

o+g=6

a+g=5.50

---------------

o-a=0.50 -----> equation 4

step 2

adds equation 1 and equation 4

a+o=5

o-a=0.50

----------------

2o=5.50

o=2.75 --------> equation 5

step 3

adds equation 2 and equation 5

a+g=5.50

o=2.75

---------------

a+o+g=8.25

therefore

the answer is $8.25