If $N=\dfrac{K}{T+\frac{x}{y}},$ where $T=\dfrac{K}5$ and $x=5-T,$ which of the following expresses $y$ in terms

Expert replies

Previous Topic Next Topic

Vincen: Legendary Member; Posts: 2898; Joined: Thu Sep 07, 2017 2:49 pmFollowed by: 5 members; Thanked: 6 times

by Vincen » Thu Sep 03, 2020 6:18 am

Timer

00:00

Your answer

Difficulty–

right wrong

Pick an answer to see how members did

If $N=\dfrac{K}{T+\frac{x}{y}},$ where $T=\dfrac{K}5$ and $x=5-T,$ which of the following expresses $y$ in terms of $N$ and $T ?$

A. $\dfrac{N(5-T)}{T(5-N)}$

B. $\dfrac{N(T-5)}{T(5-N)}$

C. $\dfrac{5-T}{T(5-N)}$

D. $\dfrac{5N(5-T)}{T(1-5N)}$

E. $\dfrac{N(5-T)}5$

Answer: A

Source: Official Guide

Source: Beat The GMAT — Problem Solving | Thu Sep 03, 2020 6:18 am

deloitte247: Legendary Member; Posts: 2214; Joined: Fri Mar 02, 2018 2:22 pmFollowed by: 5 members

Re: If $N=\dfrac{K}{T+\frac{x}{y}},$ where $T=\dfrac{K}5$ and $x=5-T,$ which of the following expresses $y$ in t

by deloitte247 » Sat Sep 05, 2020 6:28 pm

$$If\ N=\frac{K}{T+\frac{x}{y}}\ ;\ T=\frac{k}{5};\ K=5T;\ and\ x=5-T$$
$$Therefore,\ N=\frac{5T}{T+\frac{5-T}{y}}$$
Cross multiply
$$N\left(T+\frac{5-T}{y}\right)=5T$$
$$NT+\frac{N\left(5-T\right)}{y}=5T$$
$$\frac{N\left(5-T\right)}{y}=\frac{5T-NT}{1}$$
$$N\left(5-T\right)=y\left(5T-NT\right)$$
$$y=\frac{N\left(5-T\right)}{5T-NT}$$
Factorising T
$$y=\frac{N\left(5-T\right)}{T\left(5-N\right)}$$
Answer = A

GMAT/MBA Expert

Scott@TargetTestPrep: GMAT Instructor; Posts: 8246; Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members; Location: Los Angeles, CA; Thanked: 43 times

Re: If $N=\dfrac{K}{T+\frac{x}{y}},$ where $T=\dfrac{K}5$ and $x=5-T,$ which of the following expresses $y$ in t

by Scott@TargetTestPrep » Tue Sep 08, 2020 9:46 am

Vincen wrote: ↑
Thu Sep 03, 2020 6:18 am
If $N=\dfrac{K}{T+\frac{x}{y}},$ where $T=\dfrac{K}5$ and $x=5-T,$ which of the following expresses $y$ in terms of $N$ and $T ?$

A. $\dfrac{N(5-T)}{T(5-N)}$

B. $\dfrac{N(T-5)}{T(5-N)}$

C. $\dfrac{5-T}{T(5-N)}$

D. $\dfrac{5N(5-T)}{T(1-5N)}$

E. $\dfrac{N(5-T)}5$

Answer: A

Source: Official Guide

Solution:

Since T = K/5, then K = 5T. If we replace K with 5T and x with 5 - T in the first given equation, we have:

N = 5T / (T + (5 - T)/y)

N[T + (5 - T)/y] = 5T

NT + N(5 - T)/y = 5T

N(5 - T) / y = 5T - NT

N(5 - T) / y = T(5 - N)

N(5 - T) / (T(5 - N)) = y

Answer: A

Scott Woodbury-Stewart
Founder and CEO
[email protected]

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

Featured schoolRound 2 closes Jan 7, 2027 54 days left

Chicago Booth

Since 1982, 10 Booth faculty members have received the Nobel Prize in Economic Sciences, more than any other business school.

#3
U.S. News rank: $175,000
Median base salary: 670
Average GMAT Focus: 635
Students in the class

Apply to Booth Visit chicagobooth.edu See the full profile

Photo: Warren LeMay, CC BY-SA 2.0

GMAT Course Reviews

563 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (563 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review