Diana purchased 6 pounds of strawberries and 4 pounds of apples for $18.90. Then she realized that this was not enough and purchased 3 more pounds of each fruit for $10.74. What was the cost per pound for each type of fruit?

1 Answer
May 9, 2017

The strawberries cost $2.29 per pound and the apples cost $1.29 per pound.

Explanation:

Based on the question, we can assume that the cost per pound of each type of fruit is constant, meaning that the cost per pound of strawberries for the 6 pounds of strawberries is the same as the cost per pound of strawberries for the additional 3 pounds Diana bought after realizing she did not buy enough.

To solve this problem, we need to set up our system of equations:
Let #t# be the cost per pound for strawberries and #a# be the cost per pound of apples.
For both purchases, we can write the equations in word form:
(pounds of strawberries)(cost per pound of strawberries) + (pounds of apples)(cost per pound of apples) = (total cost of purchase)

For her initial purchase:
#6t+4a=18.9#
For the second purchase:
#3t+3a=10.74#

Using this system of equations of two equations and two variables, we can solve for #t# and #a#. To use elimination, we first double the second equation:
#6t+6a=21.48#
Then subtract the first equation from this modified second equation:
#6t+6a-(6t+4a)=21.48-18.9#
#6t+6a-6t-4a=2.58#
#2a=2.58#
#a=1.29#

To find t, we can substitute this value of #a# into #6t+4a=18.9# and solve for #t#:
#6t+4(1.29)=18.9#
#6t=18.9-4(1.29)#
#6t=13.74#
#t=2.29#

Therefore, the strawberries cost $2.29 per pound and the apples cost $1.29 per pound.