Last visit was: 24 Nov 2024, 08:13 It is currently 24 Nov 2024, 08:13

Close

GRE Prep 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 GRE 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
avatar
Senior Manager
Senior Manager
Joined: 20 May 2014
Posts: 285
Own Kudos [?]: 703 [0]
Given Kudos: 225
avatar
Retired Moderator
Joined: 20 Apr 2016
Posts: 1307
Own Kudos [?]: 2273 [0]
Given Kudos: 251
WE:Engineering (Energy and Utilities)
Send PM
Verbal Expert
Joined: 18 Apr 2015
Posts: 30017
Own Kudos [?]: 36370 [0]
Given Kudos: 25928
Send PM
avatar
Manager
Manager
Joined: 07 Aug 2016
Posts: 59
Own Kudos [?]: 68 [0]
Given Kudos: 0
GRE 1: Q166 V156
Send PM
Re: a, b and c are positive integers. If b equals the square roo [#permalink]
b = sqrt of a

Means b could be 1,2,3,4,5,6,7,8,9,10 etc..

A be 1,4,9,16,25,36,49,64,81,100 etc..

30 = 25 + 5

72 = 64 + 8

Other options don’t work.
Verbal Expert
Joined: 18 Apr 2015
Posts: 30017
Own Kudos [?]: 36370 [0]
Given Kudos: 25928
Send PM
a, band c are positive integers. If of a, and if c equals the sum of a [#permalink]
Expert Reply
a, band c are positive integers. If b equals the square root of a, and if c equals the sum of a and b, which of the following could be the value of c?

Indicate all such values.

A. 21
B. 30
C. 45
D. 72
E. 100
F. 331


Part of the project: GRE QCQ & PS 3 Questions Every One DAILY Challenge - (2022) - Gain 20 Kudos & Get FREE Access to GRE Prep Club TESTS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials (2022)
GRE Geometry Formulas
GRE - Math Book
Intern
Intern
Joined: 17 Sep 2022
Posts: 48
Own Kudos [?]: 48 [1]
Given Kudos: 13
Send PM
Re: a, band c are positive integers. If of a, and if c equals the sum of a [#permalink]
1
Stem a,b ,c = +ve
If b= (a)^(1/2)
c= a+b. b^2 =a

c= b^2+ b =b(b+1)
.: c= b(b+1) or (even)(odd) or (odd)(even)
.: c must be even and could the above
So A,C and F is out !!
Now B,D,and E ,let’s check even•odd
B (30= 3•10) (Even•odd ) yes!
D (72= 3•24) (Even•odd) yes!
E (100=5•20) (Even•odd) yes but E could also be (even)^2 (10•10)
Which is not a feature of C at all so and could never be so Out!

So B and D
Open to corrections though

Posted from my mobile device
Intern
Intern
Joined: 01 Oct 2022
Posts: 3
Own Kudos [?]: 1 [1]
Given Kudos: 2
Send PM
Re: a, band c are positive integers. If of a, and if c equals the sum of a [#permalink]
1
Can't 72 also be 2*36 in which case it would also not fulfill the requirement of C
I also had a confusion, does C only have to fulfill being even*odd or odd* even, doesnt it also have to be consecutive numbers since c=b(b+1)
Manager
Manager
Joined: 17 Aug 2022
Posts: 88
Own Kudos [?]: 42 [0]
Given Kudos: 73
GRE 1: Q158 V156
Send PM
a, band c are positive integers. If of a, and if c equals the sum of a [#permalink]
I solved by plugging in numbers and got the right answer as well:

If a = 4 B = 2 C = 6, see chart below:
A B C
4 2 6
9 3 12
16 4 20
25 5 30
36 6 42
64 8 72

Only B and D are correct.
Prep Club for GRE Bot
a, band c are positive integers. If of a, and if c equals the sum of a [#permalink]
Moderators:
GRE Instructor
84 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne