If Sam were twice as old as he is, he would be 40 years

This topic has expert replies
Legendary Member
Posts: 2218
Joined: Sun Oct 29, 2017 2:04 pm
Followed by:6 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

If Sam were twice as old as he is, he would be 40 years older than Jim. If Jim is 10 years younger than Sam, how old is Sam?

A. 20
B. 30
C. 40
D. 50
E. 60

The OA is B

Source: Official Guide

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Sat Jan 19, 2019 8:45 am
swerve wrote:If Sam were twice as old as he is, he would be 40 years older than Jim. If Jim is 10 years younger than Sam, how old is Sam?

A. 20
B. 30
C. 40
D. 50
E. 60
Jim is 10 years younger than Sam
Let x = Sam's PRESENT age
So, x - 10 = Jim's PRESENT age

If Sam were twice as old as he is, he would be 40 years older than Jim.
TWICE Sam's age = 2x
So, we can write: 2x = (x - 10) + 40
Simplify: 2x = x + 30
Solve: x = 30

Answer: B

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Sun Jan 20, 2019 12:10 pm
Hi All,

We're told that if Sam were TWICE as old as he is, then he would be 40 years older than Jim and that Jim is currently 10 years YOUNGER than Sam. We're asked for Sam's current age. This question can be solved in a couple of different ways, including by TESTing THE ANSWERS. Since the difference between the two ages is currently 10 years, and the answer choices are in increasing increments of 10 years, it's likely that we're dealing with one of the smaller answers (since by DOUBLING Sam's age will only increase the difference to 40 years). Let's TEST Answer B first:

Answer B: 30 years

IF... Sam is 30 years old
Jim is 30 - 10 = 20 years old
Doubling Sam's age.... (2)(30) = 60 years
60 - 20 = 40 years difference.
This matches everything that we were told, so this must be the answer.

Final Answer: B

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7222
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Sun Jan 27, 2019 9:47 am
swerve wrote:If Sam were twice as old as he is, he would be 40 years older than Jim. If Jim is 10 years younger than Sam, how old is Sam?

A. 20
B. 30
C. 40
D. 50
E. 60

The OA is B

Source: Official Guide
We can let the current ages of Sam and Jim be S and J, respectively, and create the equations:

2S = J + 40

and

J = S - 10

Substituting, we have:

2S = S - 10 + 40

S = 30

Answer: B

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage