What is the value of t?
(1) s + t = 6 + s
(2) t^3 = 216
Official Guide question
Answer: D
What is the value of t?
This topic has expert replies
-
- Senior | Next Rank: 100 Posts
- Posts: 83
- Joined: Mon Jul 24, 2017 8:16 am
- Followed by:1 members
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
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
Target question: What is the value of t?jjjinapinch wrote:What is the value of t?
(1) s + t = 6 + s
(2) t^3 = 216
Official Guide question
Answer: D
Statement 1: s + t = 6 + s
Subtract s from both sides to get: t = 6...DONE!
Since we can answer the target question with certainty, statement 1 is SUFFICIENT
Statement 2: t^3 = 216
Only one value satisfies this equation: t = 6...DONE!
Since we can answer the target question with certainty, statement 2 is SUFFICIENT
Answer: D
Cheers,
Brent
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
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
While the first statement is easy, let's discuss the second statement.jjjinapinch wrote:What is the value of t?
(1) s + t = 6 + s
(2) t^3 = 216
Official Guide question
Answer: D
If the exponent of a number is an odd integer, you get a unique value of the number.
Let's take the following examples.
1. t^2 = 36; exponent 2 is even
= t^2 = 6^2; or t^2 = (-6)^2;
In this case t = 6 or -6. No unique value.
2. t^3 = 216; exponent 3 is odd
= t^3 = 6^3; or t^3 ≠(-6)^3;
In this case t = 6. A unique value.
The correct answer: D
Hope this helps!
Download free ebook: Manhattan Review GMAT Quantitative Question Bank Guide
-Jay
_________________
Manhattan Review GMAT Prep
Locations: New York | Singapore | Doha | Lausanne | and many more...
Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.
GMAT/MBA Expert
- [email protected]
- 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
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
Hi jjjinapinch,
This prompt is built around a couple of standard Arithmetic rules. We're asked for the value of T.
1) S + T = 6 + S
If we subtract S from both sides of the equation, we get... T = 6
Fact 1 is SUFFICIENT.
2) T^3 = 216
While equations that involve exponents sometimes result in more than one solution, this equation has JUST one solution. Here's why:
(positive)^3 = positive
(negative)^3 = negative
(0)^3 = 0
Since T^3 = +216, there can be JUST ONE solution - one positive solution (and while T=6 is that solution, you don't have to technically calculate it to KNOW that there's just one solution). Thus....
Fact 2 is SUFFICIENT.
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
This prompt is built around a couple of standard Arithmetic rules. We're asked for the value of T.
1) S + T = 6 + S
If we subtract S from both sides of the equation, we get... T = 6
Fact 1 is SUFFICIENT.
2) T^3 = 216
While equations that involve exponents sometimes result in more than one solution, this equation has JUST one solution. Here's why:
(positive)^3 = positive
(negative)^3 = negative
(0)^3 = 0
Since T^3 = +216, there can be JUST ONE solution - one positive solution (and while T=6 is that solution, you don't have to technically calculate it to KNOW that there's just one solution). Thus....
Fact 2 is SUFFICIENT.
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
GMAT/MBA Expert
- Jeff@TargetTestPrep
- GMAT Instructor
- Posts: 1462
- Joined: Thu Apr 09, 2015 9:34 am
- Location: New York, NY
- Thanked: 39 times
- Followed by:22 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
We need to determine the value of t.jjjinapinch wrote:What is the value of t?
(1) s + t = 6 + s
(2) t^3 = 216
Official Guide question
Answer: D
Statement One Alone:
s + t = 6 + s
We can subtract s from both sides of the equation and obtain:
t = 6
Statement one is sufficient to answer the question.
Statement Two Alone:
t^3 = 216
We can take the cube root of t^3 and 216 and we have:
t = 6
Statement two is sufficient to answer the question.
Answer: D
Jeffrey Miller
Head of GMAT Instruction
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
1) s+t = 6+s
t=6.
statement 1) alone is sufficient.
2) t^3 = 216
t=6 (since exponent is odd so only one value will satisfy it)
statement 2) alone is also sufficient.
Option D is correct.
t=6.
statement 1) alone is sufficient.
2) t^3 = 216
t=6 (since exponent is odd so only one value will satisfy it)
statement 2) alone is also sufficient.
Option D is correct.