Last Updated on May 5, 2023
GMAT OFFICIAL GUIDE PS
Solution:
We can solve this problem by first creating equations for the given information. We know that the rate is x cents for the first pound and y cents for each pound after the first. This can be written as:
x + y(t – 1), where t is the number of pounds of the package. Let’s first determine the cost of mailing the two individual packages separately. We start with the 3-pound package:
x + y(3 – 1)
x + y(2)
x + 2y
Next we can determine the cost of mailing the 5-pound package:
x + y(5 – 1)
x + y(4)
x + 4y
Thus, the total cost for the two individual packages (if they are mailed separately) is:
x + 2y + x + 4y = 2x + 6y
Now let’s determine the cost of the two packages if they are combined as one package. The combined package would weigh 8 pounds, and its shipping cost would be:
x + y(8 – 1)
x + y(7)
x + 7y
We are given that x > y, and so we see that mailing the packages individually is more costly than mailing them as one combined package. We now need to determine the difference in cost between the two mailing options:
2x + 6y – (x + 7y)
2x + 6y – x – 7y
x – y
Thus, the savings is (x – y) cents when the packages are shipped as one combined package.
Answer: A
