Last visit was: 25 Apr 2026, 05:53 It is currently 25 Apr 2026, 05:53
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
bettatantalo
Joined: 26 Apr 2018
Last visit: 20 Nov 2018
Posts: 33
Own Kudos:
Given Kudos: 36
Posts: 33
Kudos: 162
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
CounterSniper
Joined: 20 Feb 2015
Last visit: 14 Apr 2023
Posts: 611
Own Kudos:
Given Kudos: 74
Concentration: Strategy, General Management
Posts: 611
Kudos: 859
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
dvishal387
Joined: 01 Jan 2018
Last visit: 12 Jan 2022
Posts: 62
Own Kudos:
Given Kudos: 26
Posts: 62
Kudos: 58
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
generis
User avatar
Senior SC Moderator
Joined: 22 May 2016
Last visit: 18 Jun 2022
Posts: 5,258
Own Kudos:
Given Kudos: 9,464
Expert
Expert reply
Posts: 5,258
Kudos: 37,729
Kudos
Add Kudos
Bookmarks
Bookmark this Post
bettatantalo
If \(a\) is a positive integer, then \((a+2)(a+3)(a+4)(a+5)\) is

A) even only when \(a\) is odd

B) odd whenever \(a\) is odd

C) divisible by 3 only when \(a\) is odd

D) divisible by 4 whenever \(a\) is even

There is no E) choice in this question I got given by my tutors.
Language in the correct answer has a trap.

Test numbers. What happens to
(a+2)(a+3)(a+4)(a+5)
-- When a is odd?
-- When a is even?

ODD: When a=1 then the first factor is (a + 2) = 3, so
when a is odd, (3 * 4 * 5 * 6) = 360

EVEN: When a=2, the first factor is 4.
When a is even, (4 * 5 * 6 * 7) = 840

Check options against test numbers
(a+2)(a+3)(a+4)(a+5) is

A) even only when a is odd: FALSE. From test cases:
The product (360, 840) is even when a is odd AND when a is even. REJECT

B) odd whenever a is odd: FALSE.
When a is odd, the product (360) is even, not odd. REJECT

C) divisible by 3 only when a is odd: FALSE
The product (360, 840) is divisible by 3 when a is odd AND when a is even. REJECT

D) divisible by 4 whenever a is even:
(1) TRUE
When a = 2 (even), the product of 840 is divisible by 4. KEEP

If concerned, check a = 2. First factor (4 + 2) = 6
(6 * 7 * 8 * 9) = 3,024. Divisible by 4. KEEP

(2) "Divisible by 4" is ALSO TRUE when a is odd
(When a = 1, product is 360, which is divisible by 4)
Possible trap, but:
What happens when a is odd does not matter.
#2 does not make #1 false. Option D is not asking about #2.*

Option D does not state that the product is divisible by 4 only when a is even.

D asks about the result when a is even.
Well, when a is even, the product of the factors is indeed divisible by 4.
Question asked, question answered.

Answer D

*In option D, we don't care about what happens in cases other than a = even.
Stay with what is asked. If or when a is even, is the product divisible by 4? Yes?
Then forget about what happens when a is odd. We are not being asked about that situation.
If D had stated "only when a is even," we would have a different scenario. We would have to account for what happens when ais odd.
-- ONLY WHEN implies: true for this situation AND NOT for other situations
Those "other situations" = a is odd
-- WHENEVER implies: true for this situation
Other situations do not matter.


Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
Moderator:
Math Expert
109826 posts