Last visit was: 24 Apr 2026, 14:50 It is currently 24 Apr 2026, 14:50
Home
Messages
Tests
Schools
Events
Close
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
Your Progress

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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 24 Apr 2026
Posts: 109,818
Own Kudos:
811,068
Given Kudos: 105,873
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,818
Kudos: 811,068
If a certain rift valley opens at a rate of 0.22 centimeter in 150 yea 17 May 2023, 01:30
Kudos
Add Kudos
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

35% (medium)

Question Stats:

74% (01:39) correct 26% (01:25) wrong based on 70 sessions

History

Date
Time
Result
Not Attempted Yet
If a certain rift valley opens at a rate of 0.22 centimeter in 150 years, which of the following is closest to the number of years it would take for the valley to grow 40 millimeters wider (10 millimeters is equal to one centimeter)?

A. 30
B. 270
C. 290
D. 2,730
E. 3,030


ShowHide Answer
Official Answer
D
User avatar
gmatophobia
User avatar
Quant Chat Moderator
Joined: 22 Dec 2016
Last visit: 19 Apr 2026
Posts: 3,173
Own Kudos:
11,462
 [1]
Given Kudos: 1,862
Location: India
Concentration: Strategy, Leadership
Posts: 3,173
Kudos: 11,462
 [1]
If a certain rift valley opens at a rate of 0.22 centimeter in 150 yea 17 May 2023, 07:13
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If a certain rift valley opens at a rate of 0.22 centimeter in 150 years, which of the following is closest to the number of years it would take for the valley to grow 40 millimeters wider (10 millimeters is equal to one centimeter)?

A. 30
B. 270
C. 290
D. 2,730
E. 3,030
Show more

The rift grows by 2.2 mm in 150 years.

Hence, to grow 40 millimeters wide, the required factor = \(\frac{40}{22}\) \(\approx 18.18\)

18 * 150 = 2700.

Hence, the actual value must be very close to 2700.

Option D
User avatar
Abhishek009
User avatar
Board of Directors
Joined: 11 Jun 2011
Last visit: 17 Dec 2025
Posts: 5,903
Own Kudos:
5,454
 [1]
Given Kudos: 463
Status:QA & VA Forum Moderator
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
Posts: 5,903
Kudos: 5,454
 [1]
If a certain rift valley opens at a rate of 0.22 centimeter in 150 yea 17 May 2023, 07:42
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If a certain rift valley opens at a rate of 0.22 centimeter in 150 years, which of the following is closest to the number of years it would take for the valley to grow 40 millimeters wider (10 millimeters is equal to one centimeter)?

A. 30
B. 270
C. 290
D. 2,730
E. 3,030
Show more
2.2 mm ( ie 0.22 * 10 ) in 150 Years
1 mm in 150/2.2 Years
40 mm in 150/2.2*40 = 2727.xx Years, Answer must be (D)
User avatar
hinasingh
User avatar
Joined: 05 Sep 2022
Last visit: 08 Jan 2024
Posts: 124
Own Kudos:
128
 [1]
Given Kudos: 8
Location: India
Posts: 124
Kudos: 128
 [1]
If a certain rift valley opens at a rate of 0.22 centimeter in 150 yea 17 May 2023, 10:21
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If a certain rift valley opens at a rate of 0.22cm (=2.2mm) in 150 years, which of the following is closest to the number of years it would take for the valley to grow 40 millimeters wider (10 millimeters is equal to one centimeter)?

The number of years to grow 40 mm wide = (40/2.2)*150 = 2727years

Answer D
User avatar
Gauravji21
User avatar
Joined: 27 Aug 2020
Last visit: 25 Jan 2024
Posts: 82
Own Kudos:
46
 [1]
Given Kudos: 21
Posts: 82
Kudos: 46
 [1]
If a certain rift valley opens at a rate of 0.22 centimeter in 150 yea 17 May 2023, 11:34
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If a certain rift valley opens at a rate of 0.22cm (=2.2mm) in 150 years, which of the following is closest to the number of years it would take for the valley to grow 40 millimeters wider (10 millimeters is equal to one centimeter)?

We can use unitary method for solving this question
2.2 mm in 150 years
=> 1 mm in 150/ 2.2 years or 1500 / 22 years
=> 40mm rift will be in 1500 * 40 / 2 2 = 1500 * 20 / 11 = 30000 / 1 1 ~ 30000/10 = 3000 approx
Now we have two intelligent answer choices . One is 2730 and another one is 3030. Our approximation is 3000 but we took a lower denominator (10 instead if 11). In actual, the answer should be less than 3000 because we took a lower denominator. Answer D
User avatar
chanhthang1802
User avatar
Joined: 17 Aug 2020
Last visit: 20 Mar 2026
Posts: 59
Own Kudos:
71
 [1]
Given Kudos: 14
Location: Germany
GMAT 1: 760 Q50 V42
GPA: 3.49
Products:
My Reviews
GMAT 1: 760 Q50 V42
Posts: 59
Kudos: 71
 [1]
If a certain rift valley opens at a rate of 0.22 centimeter in 150 yea 17 May 2023, 20:47
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
40 mm = 4 cm.
Therefore the number of years it would take for the valley to grow 40 millimeters wider = (4/0.22)*150 years ≈ 2727 ≈ 2730 years
The correct answer is (D).
Moderators:
Bunuel
Math Expert
109818 posts
Krunaal
Tuck School Moderator
853 posts