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Robots X, Y, and Z each assemble components at their [#permalink]
31 Mar 2009, 16:00

00:00

A

B

C

D

E

Difficulty:

35% (medium)

Question Stats:

70% (02:06) correct
30% (01:08) wrong based on 124 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?

Re: Robots X, Y, and Z each assemble [#permalink]
04 Jan 2011, 02:33

1

This post received KUDOS

Expert's post

ajit257 wrote:

see attachment

Can some explain the reasoning behind this ques.

Robots X, Y, and Z each assemble components at their respective constant rates. If rx is the ratio of robot X's constant rate to robot Z's constant rate and ry 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: DS - Rate problem / Ration problem??? - OG 12 [#permalink]
01 Apr 2009, 01:27

I think E Lets take V as Robot Z's constant rate

is Robot Z's constant rate the greatest of the three?

X:Y:Z=Va:Vb:V now to have V highest we need to know whether V is <0 or >0 V could be 2 or say, 1/2 it changes the whole picture

Robots X, Y, and Z each assemble components in their respective constant rates. If a is the ration of Robot X's constant rate to Robot Z's constant rate and b 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) a < b 2) b < 1 _________________

Re: Robots X, Y, and Z each assemble [#permalink]
03 Jan 2011, 20:26

We need both the information if the constant rate for Z is greater or not. 1. says that constant rate of Y is greater than X. x/z < x/y 2. says that constant rate of Y is smaller than Z. y/z <1

so we need both the information.

gmatclubot

Re: Robots X, Y, and Z each assemble
[#permalink]
03 Jan 2011, 20:26