Last visit was: 11 Jun 2026, 14:37 It is currently 11 Jun 2026, 14:37
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.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 11 Jun 2026
Posts: 111,216
Own Kudos:
Given Kudos: 106,759
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 111,216
Kudos: 820,115
 [18]
Kudos
Add Kudos
18
Bookmarks
Bookmark this Post
User avatar
SI777
Joined: 29 Feb 2016
Last visit: 26 Oct 2021
Posts: 93
Own Kudos:
Given Kudos: 237
Location: India
GMAT 1: 700 Q49 V35
GPA: 3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
BillyZ
User avatar
Current Student
Joined: 14 Nov 2016
Last visit: 06 Jun 2026
Posts: 1,134
Own Kudos:
Given Kudos: 926
Location: Malaysia
Concentration: General Management, Strategy
GMAT 1: 750 Q51 V40 (Online)
GPA: 3.53
Products:
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 11 Jun 2026
Posts: 16,493
Own Kudos:
79,899
 [2]
Given Kudos: 485
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,493
Kudos: 79,899
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Bunuel
If the elevation above water level of a breaching wale is given by the expression −t^2 + 12t − 35 where t is the time, in seconds, after an observer begins watching, is the whale presently underwater?

(1) t < 8.

(2) t > 5.

A breaching whale is a whale leaping out of the water.

Elevation = −t^2 + 12t − 35

(1) t < 8
Let's notice what happens at exactly t = 8
Elevation = -(8)^2 + 12*8 - 35 = -3
It means the whale is under water at this time.

Put t = 7
Elevation = -(7)^2 + 12*7 - 35 = 0
So the whale is exactly at the surface at this time.

Put t = 6
Elevation = -(6)^2 + 12*6 - 35 = 1
The whale has a positive elevation at this time.

Let's find out what happens at t = 5
Elevation = -(5)^2 + 12*5 - 35 = 0
So the whale is exactly at the surface at this time.

We see what is happening here. The whale is exactly at the surface at t = 5, is out of water and then back in the water at t = 7.

Given that t < 8, the whale is underwater if t > 7 or t < 5. Not sufficient.

(2) t > 5
If t = 6, the whale is out of water but if t > 7, it is underwater. Not sufficient.

Using both, If t = 6, the whale is out of water but if t > 7, the whale is underwater. Not sufficient.

Answer (E)
User avatar
LeopardLiu
Joined: 23 Aug 2021
Last visit: 05 Dec 2023
Posts: 90
Own Kudos:
Given Kudos: 74
Posts: 90
Kudos: 145
Kudos
Add Kudos
Bookmarks
Bookmark this Post
X has to be greater than 7.

Answer E
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 39,196
Own Kudos:
Posts: 39,196
Kudos: 1,128
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
111216 posts
377 posts