The present age of a father is 3 years more than three times the age of his son. Three years hence , father's age will be 10 years more than twice the age of the son. Present age of the father is..
A. 9
B. 10
C. 30
D. 33
E. 35
Answer: D
Source: Grockit
The present age of a father is 3 years more than three times the age of his son.
This topic has expert replies
-
- Legendary Member
- Posts: 1223
- Joined: Sat Feb 15, 2020 2:23 pm
- Followed by:1 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
GMAT/MBA Expert
- Jay@ManhattanReview
- GMAT Instructor
- Posts: 3008
- Joined: Mon Aug 22, 2016 6:19 am
- Location: Grand Central / New York
- Thanked: 470 times
- Followed by:34 members
Say father's age = x years and son's age = y yearsBTGModeratorVI wrote: ↑Thu Jul 23, 2020 6:30 amThe present age of a father is 3 years more than three times the age of his son. Three years hence , father's age will be 10 years more than twice the age of the son. Present age of the father is..
A. 9
B. 10
C. 30
D. 33
E. 35
Answer: D
Source: Grockit
=> x = 3y + 3 ---(1);
Three years hence...
x + 3 = 2(y + 3) + 10
x = 2y + 13 ---(2)
From (1) and (2), we get y = 10 and x = 33
Correct answer: D
Hope this helps!
-Jay
_________________
Manhattan Review GMAT Prep
Locations: GMAT Prep Minneapolis | GRE Prep Irvine | LSAT Prep Chicago | SAT Prep Washington DC | and many more...
Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.
BTGModeratorVI wrote: ↑Thu Jul 23, 2020 6:30 amThe present age of a father is 3 years more than three times the age of his son. Three years hence , father's age will be 10 years more than twice the age of the son. Present age of the father is..
A. 9
B. 10
C. 30
D. 33
E. 35
Answer: D
Source: Grockit
We get two equations
\begin{align*}
\begin{cases}
F = 3S + 3 \\
F + 3 = 2(S + 3) + 10
\end{cases}
\quad\Longrightarrow \quad
S=10,\quad F=33
\end{align*}
Hence, D
GMAT/MBA Expert
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7294
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
Solution:BTGModeratorVI wrote: ↑Thu Jul 23, 2020 6:30 amThe present age of a father is 3 years more than three times the age of his son. Three years hence , father's age will be 10 years more than twice the age of the son. Present age of the father is..
A. 9
B. 10
C. 30
D. 33
E. 35
Answer: D
We can let F = the present age of the father and S = the present age of the son and create the equations:
F = 3S + 3
and
F + 3 = 2(S + 3) + 10
Substituting 3S + 3 for F in the second equation, we have:
3S + 3 + 3 = 2(S + 3) + 10
3S + 6 = 2S + 6 + 10
S = 10
Therefore, the present age of the father is F = 3(10) + 3 = 33.
Answer: D
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
GMAT/MBA Expert
- Brent@GMATPrepNow
- 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
The present age of a father is 3 years more than three times the age of his sonBTGModeratorVI wrote: ↑Thu Jul 23, 2020 6:30 amThe present age of a father is 3 years more than three times the age of his son. Three years hence , father's age will be 10 years more than twice the age of the son. Present age of the father is..
A. 9
B. 10
C. 30
D. 33
E. 35
Answer: D
Source: Grockit
Let x = the PRESENT age of the son
So, 3x + 3 = the PRESENT age of the father
So, x + 3 = the son's age IN THREE YEARS
And 3x + 3 + 3 = the father's age IN THREE YEARS
Three years hence , father's age will be 10 years more than twice the age of the son
In other words: (father's age in 3 years) = 2(son's age in 3 years) + 10
In other words: (3x + 3 + 3) = 2(x + 3) + 10
Simplify: 3x + 6 = 2x + 16
Subtract 2x from both sides: x + 6 = 16
Subtract 6 from both sides: x = 10
This means the son's PRESENT age is 10 years old
Since 3x + 3 = the PRESENT age of the father, the father's present age = 3(10) + 3 = 33
Answer: D
Cheers,
Brent