BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Which of the following must be true?

Expert replies
by phanikpk » Tue Jun 24, 2014 8:05 am
Image
I have selected B based on
if x=y, then only 3 will come and we will get a prime number less than 2.
Remaining statements doesn't hold true.
Please help if I am missing anything.
OA is A [/img]
Join the discussion
Source: — Problem Solving |

by GMATinsight » Tue Jun 24, 2014 8:26 am
x could be 15 and y could be 9 and then 3x/y = (3 x 15)/9 = 5 which is prime number.

Therefore answer A is correct. None of the results is essentially true.

Cheers!!!
"GMATinsight"Bhoopendra Singh & Sushma Jha
Most Comprehensive and Affordable Video Course 2000+ CONCEPT Videos and Video Solutions
Whatsapp/Mobile: +91-9999687183 l [email protected]
Contact for One-on-One FREE ONLINE DEMO Class Call/e-mail
Most Efficient and affordable One-On-One Private tutoring fee - US$40-50 per hour
Join the discussion

by GMATGuruNY » Tue Jun 24, 2014 8:29 am
Which must be true?

I) x=y
II) y=1
III) x and y are prime integers
If 3x/y = 5, then 3x=5y.
In this case, it's possible that x=10 and y=6.
Thus, none of the options must be true.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Join the discussion

by [email protected] » Tue Jun 24, 2014 7:18 pm
Hi phanikpk,

When a GMAT Quant question asks "which of the following MUST be true?", the way to interpret this question is in the following manner:

"...which of the following is ALWAYS TRUE, NO MATTER HOW MANY DIFFERENT VARIATIONS YOU CAN THINK OF?" By definition, this will require a higher level of thinking on your part and likely a bit more work.

You did enough work to prove that X=Y COULD be true, but with a bit more work, you would have proved that it ISN'T ALWAYS true.

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Join the discussion