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

Redeem

Challenge question: If j and k are positive integers, and (k

Expert replies
by Brent@GMATPrepNow » Sun Jul 01, 2018 7:25 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty

If j and k are positive integers, and (k)(j^6) = (29^29)(11^11), then how many possible values of k are there?
A) 8
B) 10
C) 12
D) 15
E) 18

Answer: B
Difficulty level: 650-700
Source: www.gmatprepnow.com

*I'll post a solution in 2 days
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion
Source: — Problem Solving |

by GMATGuruNY » Sun Jul 01, 2018 9:04 am
Brent@GMATPrepNow wrote:If j and k are positive integers, and (k)(j^6) = (29^29)(11^11), then how many possible values of k are there?
A) 8
B) 10
C) 12
D) 15
E) 18
Options for j such that j� will divide into 29²�11¹¹:

j=1
j=11
j=29
j=29²
j=29³
j=29�
j=11*29
j=11*29²
j=11* 29³
j=11*29�

Since there are 10 options for j, there are 10 options for k.

The correct answer is B.
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 Brent@GMATPrepNow » Tue Jul 03, 2018 8:03 am
Brent@GMATPrepNow wrote:If j and k are positive integers, and (k)(j^6) = (29^29)(11^11), then how many possible values of k are there?
A) 8
B) 10
C) 12
D) 15
E) 18
Let's focus on the value of j.

Since j is an integer, it must be the case that j^6 equals some power of 6.
So, for example, j^6 could equal 29^6.
Likewise, j^6 could equal 29^12, because we can rewrite 29^12 as (29^2)^6 in which case, we can see that (29^2)^6 is a power of 6
Likewise, j^6 could equal 29^18, because we can rewrite 29^18 as (29^3)^6 in which case, we can see that (29^3)^6 is a power of 6
etc...

So, if j^6 = (29^x)(11^y), x can equal 0, 6, 12, 18 or 24 (5 different values), and y can equal 0 or 6 (2 different values)
If x can have 5 different values, and y can have 2 different values, then the number of ways to assign values to x and y = (5)(2) = 10
This means j^6 can have 10 different values, which means k can also have 10 different values.

Answer: B

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion