Last visit was: 21 Dec 2024, 21:42 It is currently 21 Dec 2024, 21:42

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
User avatar
Retired Moderator
Joined: 07 Jun 2014
Posts: 4815
Own Kudos [?]: 11266 [12]
Given Kudos: 0
GRE 1: Q167 V156
WE:Business Development (Energy and Utilities)
Send PM
Most Helpful Community Reply
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12234 [6]
Given Kudos: 136
Send PM
General Discussion
Retired Moderator
Joined: 07 Jan 2018
Posts: 739
Own Kudos [?]: 1462 [2]
Given Kudos: 93
Send PM
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12234 [0]
Given Kudos: 136
Send PM
Re: GRE Math Challenge #14 - 72.42= k(24 + n/100) [#permalink]
1
amorphous wrote:
if \(K = 100\) and \(n = - 2327.58\)

This satisfies the eqn and condition and their sum is \(-2227.58\)


Good point!
I have added a restriction to n to prevent more than 1 correct answer.

Cheers,
Brent
User avatar
Manager
Manager
Joined: 19 Nov 2018
Posts: 102
Own Kudos [?]: 159 [0]
Given Kudos: 0
Send PM
Re: GRE Math Challenge #14 - 72.42= k(24 + n/100) [#permalink]
1
Interesting solution. I don't think I would have ever guessed. It makes sense when you write it all out, but it's like you saw a path that was completely hidden, at least from non-math people.
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12234 [3]
Given Kudos: 136
Send PM
Re: GRE Math Challenge #14 - 72.42= k(24 + n/100) [#permalink]
2
1
Bookmarks
sandy wrote:
If 0 < n < 100 and 72.42 = k(24 + n/100), then k + n =


Here's another approach:

GIVEN: \(72.42 = k(24 + \frac{n}{100})\)

Expand right side: \(72.42 = 24k+\frac{kn}{100}\)

Multiply both sides by 100 to get: \(7242 = 2400k+kn\)

Factor out the k to get: \(7242 = k(2400+n)\)

ASIDE: Since n is POSITIVE, we know that k is positive.
Since \((3)(2400)=7200\), and since 7200 is pretty close to 7242, let's see how things look if we try factoring a 3 from the left side of the equation.

We get: \(3(2414)= k(2400+n)\)

We can rewrite 2414 as follows: \(3(2400+14)= k(2400+n)\)

At this point, we can see that \(k=3\) and \(n=14\)

So, \(k+n=3+14=17\)

Answer: 17

Cheers,
Brent
avatar
Intern
Intern
Joined: 11 Jul 2019
Posts: 33
Own Kudos [?]: 30 [0]
Given Kudos: 0
Send PM
Re: GRE Math Challenge #14 - 72.42= k(24 + n/100) [#permalink]
1
this type of problem is beyond complicated and it definitely takes more than 2 min to solve.
avatar
Intern
Intern
Joined: 02 Jul 2020
Posts: 2
Own Kudos [?]: 0 [0]
Given Kudos: 0
Send PM
Re: GRE Math Challenge #14 - 72.42= k(24 + n/100) [#permalink]
I do not understand how you are able to conclude that 24k = 72 and kn/100 = 42/100 if we do not know the value of k?
Manager
Manager
Joined: 09 Nov 2018
Posts: 88
Own Kudos [?]: 95 [0]
Given Kudos: 0
Send PM
Re: GRE Math Challenge #14 - 72.42= k(24 + n/100) [#permalink]
1
Quote:
If 0 < n < 100 and 72.42 = k(24 + n/100), then k + n =

Step 1: Understanding the question
Here value of n lies between 0 to 100 and respective value of k can be calculated

Step 2: Calculation
When n = 10,
72.42 = k(24 + 10/100)
k = \(\frac{72.42 }{ 24.1}\) = 3.004, hence n + k = 10 + 3 = 13 (approx)

When n = 20
72.42 = k(24 + 20/100)
k = \(\frac{72.42 }{ 24.2}\) = 3 (approx), here value of n + k = 20 + 3 = 23 (approx)

As n lies between 0 to 100, there will be multiple values of k and hence of n+k.
Therefore, there is no specific value for n + k.
User avatar
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 5088
Own Kudos [?]: 76 [0]
Given Kudos: 0
Send PM
Re: GRE Math Challenge #14 - 72.42= k(24 + n/100) [#permalink]
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Prep Club for GRE Bot
Re: GRE Math Challenge #14 - 72.42= k(24 + n/100) [#permalink]
Moderators:
GRE Instructor
88 posts
GRE Forum Moderator
37 posts
Moderator
1115 posts
GRE Instructor
234 posts

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