It is currently 22 Jan 2018, 02:28

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close

Author Message
TAGS:

### Hide Tags

Joined: 27 Sep 2015
Posts: 58
GMAT 1: 410 Q33 V13
WE: Management Consulting (Computer Software)
If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close [#permalink]

### Show Tags

19 Dec 2015, 10:53
00:00

Difficulty:

5% (low)

Question Stats:

82% (01:28) correct 18% (01:09) wrong based on 72 sessions

### HideShow timer Statistics

If $$v=\sqrt{\frac{2(9.8)m}{(0.5)j}}$$, m = 96 and j = 49, which of the following most closely approximates the value of v?

(A) 0
(B) 9
(C) 17
(D) 25
(E) 33

[Reveal] Spoiler:
I used the ball- parking strategy to easy calculate ugly number:

√(2(8) 100 / 1/2*50) = √(16*100/25) = 4*10/5 = 8

Number 8 is very close to 9 in answers.

[Reveal] Spoiler: OA

_________________

Discipline does not mean control. Discipline means having the sense to do exactly what is needed.

Last edited by Bunuel on 30 Nov 2017, 19:56, edited 5 times in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.
Magoosh GMAT Instructor
Joined: 28 Dec 2011
Posts: 4647
Re: If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close [#permalink]

### Show Tags

19 Dec 2015, 14:54
1
KUDOS
Expert's post
Rsohal wrote:
If v = √2(9.8)m / 0.5j , m=96 and j=49, which of the following most closely approximates the value of v?

(A) 0
(B) 9
(C) 17
(D) 25
(E) 33

I used the ball- parking strategy to easy calculate ugly number:

√2(8) 100 / 1/2*50 = √16*100/25 = 4*10/5 = 8

Number 8 is very close to 9 in answers.

Dear Rsohal,
I'm happy to respond.

I gather that you are new to GMAT Club. A few points to observe. First of all, this particular subforum, "Ask GMAT Experts," is for general advice on test-taking strategies, questions about scheduling and retakes and logistics of the test, etc. This is not the correct forum at all for individual math questions, such as this. This should have been posted in the general math forum, in the problem solving section:
gmat-problem-solving-ps-140/

I would be happy to respond, but unfortunately, I believe you have made mathematical mistakes in posting the question. It appears that you don't have a refined understanding of mathematical grouping symbols. For more on these, see:
http://magoosh.com/gmat/2013/gmat-quant ... g-symbols/
I say this because you use the "√" character, but you give no indication of how much is included under the square root. Typically, in the rtf of GC, one would use parentheses for this. There is a world of difference between
√(2)(9.8)m / 0.5j
and
√(2(9.8)m) / 0.5j
and
√(2(9.8)m / 0.5j)
These ambiguities need to be clarified before the question is mathematical sensible.

Does all this make sense?
Mike
_________________

Mike McGarry
Magoosh Test Prep

Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)

Joined: 27 Sep 2015
Posts: 58
GMAT 1: 410 Q33 V13
WE: Management Consulting (Computer Software)
Re: If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close [#permalink]

### Show Tags

19 Dec 2015, 18:05
Thanks Mike for your reply. You are right. When i typed question, I could not draw square root bar, which was in text book. Anyhow, your suggestion was absolutely correct. I have edited question for better understanding.

thanks for help. much appreciated.
_________________

Discipline does not mean control. Discipline means having the sense to do exactly what is needed.

Magoosh GMAT Instructor
Joined: 28 Dec 2011
Posts: 4647
Re: If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close [#permalink]

### Show Tags

20 Dec 2015, 08:56
1
KUDOS
Expert's post
Rsohal wrote:
If v = √(2(9.8)m / 0.5j) , m=96 and j=49, which of the following most closely approximates the value of v?

(A) 0
(B) 9
(C) 17
(D) 25
(E) 33

I used the ball- parking strategy to easy calculate ugly number:

√(2(8) 100 / 1/2*50) = √(16*100/25) = 4*10/5 = 8

Number 8 is very close to 9 in answers.

Dear Rsohal,
Your approximation approach is an excellent for this and many other official questions. Here, as I glance over the problem, I happen to notice that
49*2 = 98. This allows for a little simplification.
v = $$\sqrt{\frac{2(9.8)m}{0.5j}}$$
v = $$\sqrt{\frac{2(9.8)(96)}{(0.5)(49)}}$$
v = $$\sqrt{\frac{4(9.8)(96)}{(0.5)(98)}}$$
v = $$\sqrt{\frac{4(98)(96)}{(5)(98)}}$$
v = $$\sqrt{\frac{4(96)}{5}}$$
v = $$\sqrt{\frac{4(16*6)}{5}}$$
v = $$2\sqrt{\frac{(16*6)}{5}}$$
v = $$8\sqrt{\frac{6}{5}}$$
v = $$8\sqrt{1.2}$$
We know that $$\sqrt{1}=1$$ and $$\sqrt{1.21}=1.1$$, so
$$8\sqrt{1} < v < 8\sqrt{1.21}$$
8*1 < v < 8*1.1
8 < v < 8.8
This approximates the decimal to a relatively small band. From a calculator, I found the exact answer is 8.76356. Of the answer choices, 9 is clearly the closest.

I hope this helps, my friend.
Mike
_________________

Mike McGarry
Magoosh Test Prep

Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)

Last edited by mikemcgarry on 20 Dec 2015, 17:58, edited 2 times in total.
Joined: 27 Sep 2015
Posts: 58
GMAT 1: 410 Q33 V13
WE: Management Consulting (Computer Software)
Re: If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close [#permalink]

### Show Tags

20 Dec 2015, 12:21
1
KUDOS
Mike,

There is one issue in following equation, when you input value of variables.
You made j = 49*2, where as J is 49.
If you multiply j with 2, you must multiply upper part of fraction to 2 as well.

v = $$\sqrt{\frac{2(9.8)(96)}{(0.5)(98)}}$$

above equation should be

v = $$\sqrt{\frac{2(9.8)(96)2}{(0.5)(98)}}$$

Thanks
_________________

Discipline does not mean control. Discipline means having the sense to do exactly what is needed.

Magoosh GMAT Instructor
Joined: 28 Dec 2011
Posts: 4647
Re: If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close [#permalink]

### Show Tags

20 Dec 2015, 18:00
Rsohal wrote:
Mike,

There is one issue in following equation, when you input value of variables.
You made j = 49*2, where as J is 49.
If you multiply j with 2, you must multiply upper part of fraction to 2 as well.

v = $$\sqrt{\frac{2(9.8)(96)}{(0.5)(98)}}$$

above equation should be

v = $$\sqrt{\frac{2(9.8)(96)2}{(0.5)(98)}}$$

Thanks

Dear Rsohal,
My friend, thanks for catching that! I simply plugged the wrong value of j into the equation. I edited my response above, so that it won't confuse others.
Mike
_________________

Mike McGarry
Magoosh Test Prep

Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)

Senior Manager
Joined: 13 Oct 2016
Posts: 290
GMAT 1: 600 Q44 V28
Re: If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close [#permalink]

### Show Tags

30 Nov 2017, 16:55
1
KUDOS
RSOHAL wrote:
If v = $$\sqrt{\frac{2(9.8)m}{(0.5)j}}$$, m=96 and j=49, which of the following most closely approximates the value of v?

(A) 0
(B) 9
(C) 17
(D) 25
(E) 33

I used the ball- parking strategy to easy calculate ugly number:

√(2(8) 100 / 1/2*50) = √(16*100/25) = 4*10/5 = 8

Number 8 is very close to 9 in answers.

Hi Bunuel ,

Could you please move the above question to the Problem Solving section.
_________________

_______________________________________________
If you appreciate the post then please click +1Kudos

Math Expert
Joined: 02 Sep 2009
Posts: 43363
Re: If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close [#permalink]

### Show Tags

30 Nov 2017, 19:57
Kritesh wrote:
RSOHAL wrote:
If v = $$\sqrt{\frac{2(9.8)m}{(0.5)j}}$$, m=96 and j=49, which of the following most closely approximates the value of v?

(A) 0
(B) 9
(C) 17
(D) 25
(E) 33

I used the ball- parking strategy to easy calculate ugly number:

√(2(8) 100 / 1/2*50) = √(16*100/25) = 4*10/5 = 8

Number 8 is very close to 9 in answers.

Hi Bunuel ,

Could you please move the above question to the Problem Solving section.

______________
Done. Thank you.
_________________
Re: If v = 2(9.8)m/(0.5j), m=96 and j=4, which of the following most close   [#permalink] 30 Nov 2017, 19:57
Display posts from previous: Sort by