Reading Time: < 1 minute
Last Updated on May 5, 2023
GMAT OFFICIAL GUIDE PS
Solution:
To solve, we will set up two equations. Let’s start by defining two variables.
J = number of dollars Jim has
L = number of dollars Lois has
We are given that Lois has x dollars more than Jim. We set up an equation:
L = x + J
We are next given that together they have a total of y dollars. We can set up our second equation:
J + L = y
Since we know that L = x + J, we can substitute x + J for L into the second equation J + L = y.
Notice that, after the substitution, we will only have variables of J, x, and y. Thus, we have:
J + x + J = y
2J + x = y
2J = y – x
J = (y – x)/2
Answer: A
