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 GMAT 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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Robots X, Y, and Z each assemble components at their respect [#permalink]
24 Sep 2012, 04:16

Expert's post

3

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

25% (medium)

Question Stats:

69% (02:26) correct
31% (01:15) wrong based on 262 sessions

Robots X, Y, and Z each assemble components at their respective constant rates. If r_x is the ratio of Robot X's constant rate to Robot Z's constant rate and r_y is the ratio of Robot Y's constant rate to Robot Z's constant rate, is Robot Z's constant rate the greatest of the three?

(1) r_x<r_y (2) r_y<1

Practice Questions Question: 47 Page: 279 Difficulty: 600

Re: Robots X, Y, and Z each assemble components at their respect [#permalink]
24 Sep 2012, 04:16

3

This post received KUDOS

Expert's post

1

This post was BOOKMARKED

Robots X, Y, and Z each assemble components at their respective constant rates. If r_x is the ratio of Robot X's constant rate to Robot Z's constant rate and r_y is the ratio of Robot Y's constant rate to Robot Z's constant rate, is Robot Z's constant rate the greatest of the three?

Let the rates of robots X, Y, and Z be x, y, and z respectively. Given: r_x=\frac{x}{z} and r_y=\frac{y}{z}. Question is z>x and z>y?

(1) r_x<r_y --> \frac{x}{z}<\frac{y}{z} --> x<y. Not sufficient.

(2) r_y<1 --> \frac{y}{z}<1 --> y<z. Not sufficient.

Re: Robots X, Y, and Z each assemble components at their respect [#permalink]
24 Sep 2012, 07:23

1

This post received KUDOS

Robots X, Y, and Z each assemble components at their respective constant rates. If is the ratio of Robot X's constant rate to Robot Z's constant rate and is the ratio of Robot Y's constant rate to Robot Z's constant rate, is Robot Z's constant rate the greatest of the three?

(1) INSUFF X/z < Y/z this does not allow us to pin point anything to do with z (2) INSUFF y/z<1 again, not enough, y could make 1 an hour and z could make 2 an hour or 2,000 per hour. However, we don't know anything about X Together, SUFF X/z < y/z < 1 We know that z is faster than Y and we know that Y is faster than X - the question is true _________________

If you find my post helpful, please GIVE ME SOME KUDOS!

Re: Robots X, Y, and Z each assemble components at their respect [#permalink]
24 Sep 2012, 08:02

Bunuel wrote:

Robots X, Y, and Z each assemble components at their respective constant rates. If r_x is the ratio of Robot X's constant rate to Robot Z's constant rate and r_y is the ratio of Robot Y's constant rate to Robot Z's constant rate, is Robot Z's constant rate the greatest of the three?

(1) r_x<r_y (2) r_y<1

(1) Since r_x and r_y are RATIO of rates of X and Y wrt to Z respectively, if we compare these two the rate of Z will cancel out from both sides and we will be left with X < Y. Nothing is know about Z. Not sufficient

(2) Here, ration of rate of Y to Z is lesser than 1. Thus Y < Z. Nothing is known about X. So not sufficient.

combining (1) and (2), X < Y < Z, Z has greatest rate.

Re: Robots X, Y, and Z each assemble components at their respect [#permalink]
28 Sep 2012, 04:12

Expert's post

Robots X, Y, and Z each assemble components at their respective constant rates. If r_x is the ratio of Robot X's constant rate to Robot Z's constant rate and r_y is the ratio of Robot Y's constant rate to Robot Z's constant rate, is Robot Z's constant rate the greatest of the three?

Let the rates of robots X, Y, and Z be x, y, and z respectively. Given: r_x=\frac{x}{z} and r_y=\frac{y}{z}. Question is z>x and z>y?

(1) r_x<r_y --> \frac{x}{z}<\frac{y}{z} --> x<y. Not sufficient.

(2) r_y<1 --> \frac{y}{z}<1 --> y<z. Not sufficient.

(1)+(2) As x<y and y<z then x<y<z. Sufficient.

Answer: C.

Kudos points given to everyone with correct solution. Let me know if I missed someone. _________________

Re: Robots X, Y, and Z each assemble components at their respect [#permalink]
23 Jun 2014, 23:35

Hello from the GMAT Club BumpBot!

Thanks to another GMAT 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. _________________

Re: Robots X, Y, and Z each assemble components at their respect [#permalink]
06 Oct 2014, 11:34

I took ratios for robots X, Y, Z - 1/x, 1/y and 1/z respectively. therefore I made a mistake, and answered B since 1/y : 1/z = 1/y*z/1 = z/y and if Ry<1 then Z is less then Y...

Robots X, Y, and Z each assemble components at their respect [#permalink]
10 Oct 2014, 10:27

mvictor wrote:

I took ratios for robots X, Y, Z - 1/x, 1/y and 1/z respectively. therefore I made a mistake, and answered B since 1/y : 1/z = 1/y*z/1 = z/y and if Ry<1 then Z is less then Y...

No its alright to do so Here's something that will help you

let the rates be 1/x for X, 1/y for Y and 1/z for Z so Rx= 1/x/1/z = z/x and similarly Ry= 1/y/1/z = z/y

statement 1 --> Rx<Ry --> z/x<z/y --> x>y (since z is constant for example z=1 , x=4 and y= 2 --> Rx<Ry --> x>y) Nothing is said about z here so insufficient

statement 2 --> Ry<1 --> z/y<1 --> z<y (cross multiply, its okay to do so here as rates cannot be negative ) nothing about x so insufficient

statement 1 & 2 together

z<y<x is z the greatest? clearly not

so answer is C

Hope it helps, if it does a Kudos will be great. Cheers!!

Re: Robots X, Y, and Z each assemble components at their respect [#permalink]
10 Oct 2014, 10:30

Bunuel wrote:

Robots X, Y, and Z each assemble components at their respective constant rates. If r_x is the ratio of Robot X's constant rate to Robot Z's constant rate and r_y is the ratio of Robot Y's constant rate to Robot Z's constant rate, is Robot Z's constant rate the greatest of the three?

Let the rates of robots X, Y, and Z be x, y, and z respectively. Given: r_x=\frac{x}{z} and r_y=\frac{y}{z}. Question is z>x and z>y?

(1) r_x<r_y --> \frac{x}{z}<\frac{y}{z} --> x<y. Not sufficient.

(2) r_y<1 --> \frac{y}{z}<1 --> y<z. Not sufficient.

(1)+(2) As x<y and y<z then x<y<z. Sufficient.

Answer: C.

Kudos points given to everyone with correct solution. Let me know if I missed someone.

Hi Bunuel,

Could you kindly check my approach?

Thanks

let the rates be 1/x for X, 1/y for Y and 1/z for Z so Rx= 1/x/1/z = z/x and similarly Ry= 1/y/1/z = z/y

statement 1 --> Rx<Ry --> z/x<z/y --> x>y (since z is constant for example z=1 , x=4 and y= 2 --> Rx<Ry --> x>y) Nothing is said about z here so insufficient

statement 2 --> Ry<1 --> z/y<1 --> z<y (cross multiply, its okay to do so here as rates cannot be negative ) nothing about x so insufficient

statement 1 & 2 together

z<y<x is z the greatest? clearly not

so answer is C

gmatclubot

Re: Robots X, Y, and Z each assemble components at their respect
[#permalink]
10 Oct 2014, 10:30