OG2015 PS Lois has x dollars

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OG2015 PS Lois has x dollars

by lionsshare » Wed Sep 13, 2017 9:34 pm
Lois has x dollars more than Jim has, and together they have a total of y dollars. Which of the following represents the number of dollars that Jim has?

(A) (y - x)/2
(B) y - x/2
(C) y/2 - x
(D) 2y - x
(E) y - 2x

OA: A

Hi, Experts. Please share the solution to this problem. Thanks.

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by Jay@ManhattanReview » Wed Sep 13, 2017 9:43 pm
lionsshare wrote:Lois has x dollars more than Jim has, and together they have a total of y dollars. Which of the following represents the number of dollars that Jim has?

(A) (y - x)/2
(B) y - x/2
(C) y/2 - x
(D) 2y - x
(E) y - 2x

OA: A

Hi, Experts. Please share the solution to this problem. Thanks.
Say Lois has $L, and Jim has $J.

Thus, as per the condition: "Lois has x dollars more than Jim has," we get

L - J = x ---(1)

As per the second condition: "together they have a total of y dollars," we get

L + J = y ---(2)

Since we want to find out the amount of money Jim has, let's subtract (1) from (2).

We get (L + J = y) - (L - J = x)

L + J - L + J = y - x

2J = y - x

J = (y - x)/2

The correct answer: A

Hope this helps!

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by Brent@GMATPrepNow » Thu Sep 14, 2017 6:36 am
lionsshare wrote:Lois has x dollars more than Jim has, and together they have a total of y dollars. Which of the following represents the number of dollars that Jim has?

(A) (y - x)/2
(B) y - x/2
(C) y/2 - x
(D) 2y - x
(E) y - 2x
Let J = number of dollars that Jim has

Lois has x dollars more than Jim has
So, J + x = number of dollars that Lois has

Together they have a total of y dollars
So, (Jim's $) + (Lois' $) = y
Or: J + (J+x) = y
Simplify: 2J + x = y

Which of the following represents the number of dollars that Jim has?
Solve 2J + x = y for J
Subtract x from both sides to get: 2J = y - x
Divide both sides by 2 to get: (y-x)/2

Answer: A

Cheers,
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by [email protected] » Thu Sep 14, 2017 11:19 am
Hi lionsshare,

We're told that Lois has X dollars MORE than Jim has and together they have a TOTAL of Y dollars. We're asked for the number of dollars that Jim has. This question can be solved by TESTing VALUES.

IF....
Lois has 5 dollars and Jim has 2 dollars, then X = 3 and Y = 7. So we're looking for an answer that equals 2 when we plug in X = 3 and Y = 7... There's only one answer that matches:

Final Answer: A

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by Jeff@TargetTestPrep » Tue Sep 19, 2017 2:54 pm
lionsshare wrote:Lois has x dollars more than Jim has, and together they have a total of y dollars. Which of the following represents the number of dollars that Jim has?

(A) (y - x)/2
(B) y - x/2
(C) y/2 - x
(D) 2y - x
(E) y - 2x

OA: A
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 the following 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 in 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

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