The number of rooms at Hotel G is 10 less than twice the num

This topic has expert replies
Moderator
Posts: 426
Joined: Tue Aug 22, 2017 8:48 pm
Followed by:1 members
The number of rooms at Hotel G is 10 less than twice the number of rooms at Hotel H. If the total number of rooms at Hotel G and Hotel H is 425, what is the number of rooms at Hotel G?

(A) 140
(B) 180
(C) 200
(D) 240
(E) 280

OA: E

Is there a strategic approach to this question? . Can any experts help?

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members

by Jay@ManhattanReview » Wed Jan 17, 2018 2:52 am
ardz24 wrote:The number of rooms at Hotel G is 10 less than twice the number of rooms at Hotel H. If the total number of rooms at Hotel G and Hotel H is 425, what is the number of rooms at Hotel G?

(A) 140
(B) 180
(C) 200
(D) 240
(E) 280

OA: E

Is there a strategic approach to this question? . Can any experts help?
Pl. find it here https://www.beatthegmat.com/the-number-o ... 99884.html

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Singapore | London | Dubai | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Wed Jan 17, 2018 3:36 am
ardz24 wrote:The number of rooms at Hotel G is 10 less than twice the number of rooms at Hotel H. If the total number of rooms at Hotel G and Hotel H is 425, what is the number of rooms at Hotel G?

(A) 140
(B) 180
(C) 200
(D) 240
(E) 280
We can PLUG IN THE ANSWERS, which represent the number of rooms at G.
When the correct answer is plugged in, the number of rooms at G will be 10 less than twice the number of rooms at H.

D: G = 240
Since the total number of rooms at G and H = 425, H = 425-240 = 185.
10 less than twice H = (2*185) - 10 = 360.
Here, G is LESS than the value in blue, implying that the value of G must be BIGGER.

The correct answer is E.

E: G = 280
Since the total number of rooms at G and H = 425, H = 425-280 = 145.
10 less than twice H = (2*145) - 10 = 280.
Success!
G is equal to the value in blue.

Algebra:
Since G is equal to 10 less than twice H, we get:
G = 2H - 10

Since the total number of rooms at G and H is 425, we get:
G + H = 425
H = 425 - G

Substituting H = 425-G into G = 2H - 10, we get:
G = 2(425-G) - 10
G = 850 - 2G - 10
3G = 840
G = 280.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

Senior | Next Rank: 100 Posts
Posts: 82
Joined: Mon Jan 15, 2018 2:01 am

by DrMaths » Wed Jan 17, 2018 5:24 am
Substitute H (= 425 - G) into G = 2H - 10
to get G = 2(425-G) -10
So, G = 850 -2G - 10
So 3G = 840
then G = 840/3 = 280

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
ardz24 wrote:The number of rooms at Hotel G is 10 less than twice the number of rooms at Hotel H. If the total number of rooms at Hotel G and Hotel H is 425, what is the number of rooms at Hotel G?

(A) 140
(B) 180
(C) 200
(D) 240
(E) 280
We can also solve the question using 1 variable

Let x = number of rooms at Hotel H

The number of rooms at Hotel G is 10 less than twice the number of rooms at Hotel H
So, 2x - 10 = number of rooms at Hotel G

The total number of rooms at Hotel G and Hotel H is 425
We can write: x + (2x - 10) = 425
Simplify: 3x - 10 = 425
Solve: x = 145

2x - 10 = number of rooms at Hotel G
So, the number of rooms at Hotel G = 2(145) - 10
= 280

Answer: E

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] » Wed Jan 17, 2018 10:36 am
Hi ardz24,

We're told that the number of rooms at Hotel G is 10 less than twice the number of rooms at Hotel H and that the total number of rooms at Hotel G and Hotel H is 425. We're asked for the number of rooms at Hotel G. This question can be solved by TESTing THE ANSWERS.

To start, we have a total of 425 rooms and we're told that Hotel G has 10 less than TWICE the rooms at Hotel H, so Hotel G clearly has a LOT more rooms than Hotel H does. Thus, we should start with one of the larger answers. Let's TEST Answer D.

IF.... Hotel G has 240 rooms
240 is 10 less than twice (H)
240 = 2H - 10
250 = 2H
125 = H
In this scenario, there would be 240+125 = 365 rooms. This is clearly TOO SMALL though (there are supposed to be 425 rooms), so we need both hotels to have more rooms. There's only one answer that allows for that.... If you want to prove the correct answer though, it would just take a bit more math...

IF.... Hotel G has 280 rooms
280 is 10 less than twice (H)
280 = 2H - 10
290 = 2H
145 = H
In this scenario, there would be 280+145 = 425 rooms. This is an exact match for what we were told, so this MUST be the answer.

Final Answer: E

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

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7243
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Mon Aug 05, 2019 6:12 pm
BTGmoderatorAT wrote:The number of rooms at Hotel G is 10 less than twice the number of rooms at Hotel H. If the total number of rooms at Hotel G and Hotel H is 425, what is the number of rooms at Hotel G?

(A) 140
(B) 180
(C) 200
(D) 240
(E) 280
We can let the number of rooms in hotel G = g and the number of rooms in hotel H = h and create the two equations:

g = 2h - 10

and

g + h = 425

Substituting the first equation for g in the second equation, we have:

2h - 10 + h = 425

3h = 435

h = 145

So g = 2(145) - 10 = 280.

Answer: E

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