Rob is twice as old as Jodie is now. In 10 years, Rob will be 20 years older than Jodie is at that time. How old is Jodie now?
A. 10
B. 20
C. 30
D. 40
E. 50
The OA is B
Source: Princeton Review
Word Problems
This topic has expert replies
-
- Legendary Member
- Posts: 2214
- Joined: Fri Mar 02, 2018 2:22 pm
- Followed by:5 members
Let Rob's age now = r
Let Jodie's age now = j
r = 2j ----- eqn (1)
In 10 years time =>
r + 10 = (j + 10) + 20
r + 10 = j + 30
r = j + 20 where r = 2j
2j = j + 20
j = 20 years
Answer = option B
Let Jodie's age now = j
r = 2j ----- eqn (1)
In 10 years time =>
r + 10 = (j + 10) + 20
r + 10 = j + 30
r = j + 20 where r = 2j
2j = j + 20
j = 20 years
Answer = option B
GMAT/MBA Expert
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7247
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
Solution:
We can let R = Rob’s current age and J = Jodie’s current age and create the equation:
R = 2J
If Rob will be 20 years older than Jodie in 10 years, he must also be 20 years older than she is presently. Thus, we have:
R = J + 20
Substituting, we have:
2J = J + 20
J = 20
Answer: B
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews