 It is currently 22 Jul 2019, 18:40 ### 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

#### Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here. # If a , b , and c are consecutive odd integers, which express  Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Founder  Joined: 18 Apr 2015
Posts: 7426
Followers: 126

Kudos [?]: 1457 , given: 6628

If a , b , and c are consecutive odd integers, which express [#permalink]
Expert's post 00:00

Question Stats: 69% (00:49) correct 30% (00:52) wrong based on 23 sessions

If a, b, and c are consecutive odd integers, which expression must be odd?

Choose $$all$$ that apply.

❑ $$a*(b+c)$$

❑ $$(a+b) - c$$

❑ $$a*b*c$$

❑ $$2*(c-a) + b$$

❑ $$a + b + c$$
[Reveal] Spoiler: OA

_________________ Director Joined: 03 Sep 2017
Posts: 520
Followers: 1

Kudos [?]: 363  , given: 66

Re: If a , b , and c are consecutive odd integers, which express [#permalink]
1
KUDOS
Let's check them one by one

❑ $$a*(b+c)$$ -> odd+odd = even, odd*even = even, so it must be even

❑ $$(a+b) - c$$ -> odd+odd = odd, odd-odd = odd, so it must be odd

❑ $$a*b*c$$ -> odd*odd = odd, so it must be odd

❑ $$2*(c-a) + b$$ -> odd-odd = odd, even*odd = even, even+odd = odd, so it must be odd

❑ $$a + b + c$$ -> odd+odd = even, even+odd = odd, so it must be odd

Then, the answers are B, C, D, E. GRE Instructor Joined: 10 Apr 2015
Posts: 2177
Followers: 65

Kudos [?]: 1994  , given: 20

Re: If a , b , and c are consecutive odd integers, which express [#permalink]
1
KUDOS
Expert's post
Carcass wrote:

If a, b, and c are consecutive odd integers, which expression must be odd?

Choose $$all$$ that apply.

A) $$a*(b+c)$$

B) $$(a+b) - c$$

C) $$a*b*c$$

D) $$2*(c-a) + b$$

E) $$a + b + c$$

To solve this question, we can EITHER apply the rules for ODDS and EVENS (as IlCreatore has done) or we can plug in 3 consecutive ODD integers for a, b and c
How about a = 1, b = 3 and c = 3

We get:

A) $$1*(3+5) = 8$$, which is EVEN. ELIMINATE.

B) $$(1+3) - 5 = -1$$, which is ODD. KEEP!

C) $$1*3*5 = 15$$, which is ODD. KEEP!

D) $$2*(5-1) + 3 = 11$$, which is ODD. KEEP!

E) $$1 + 3 + 5 = 9$$, which is ODD. KEEP!

Cheers,
Brent
_________________

Brent Hanneson – Creator of greenlighttestprep.com  Re: If a , b , and c are consecutive odd integers, which express   [#permalink] 22 Jan 2019, 07:13
Display posts from previous: Sort by

# If a , b , and c are consecutive odd integers, which express  Question banks Downloads My Bookmarks Reviews Important topics Powered by phpBB © phpBB Group Kindly note that the GRE® test is a registered trademark of the Educational Testing Service®, and this site has neither been reviewed nor endorsed by ETS®.