gmat prep question

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 53
Joined: Thu Apr 12, 2007 12:32 am
Thanked: 1 times

gmat prep question

by jc114 » Mon May 14, 2007 7:12 am
A restaurant receives clean uniforms on May 3 and every 7 days thereafter. The restaurant receives clean linens on May 4 and every 5 days thereafter. On what date in May does the restaurant receive both clean uniforms and clean linens?
A. may 3
B. may 10
C. may 17
D. may 19
E. may 24

If y= x^2-5x+14 and z= x^2-x+2, what is the set of all values of x for which y=2z?
A. (-5)
B. (2)
C. (3)
D. (-2, 5)
E. (-5,2)
Source: — Problem Solving |

Master | Next Rank: 500 Posts
Posts: 105
Joined: Mon Sep 18, 2006 12:34 pm
Location: OH
Thanked: 7 times
GMAT Score:780

by mschling52 » Mon May 14, 2007 10:19 am
1. Simplest way I see to do this one is just to list the days. Since all the answer options are in May, you know you won't have to go too far out to find a common day. So,

Uniforms - May 3rd, 10th, 17th, 24th, 31st
Linens - May 4th, 9th, 14th, 19th, 24th, 29th

E.

2. We have equations for y and z both in terms of x. Therefore, we can write y=2z as

x^2 - 5x + 14 = 2(x^2 - x + 2)
x^2 - 5x + 14 = 2(x^2) - 2x + 4
0 = x^2 + 3x -10
0 = (x-2)(x+5)

So, x = 2 or -5

Legendary Member
Posts: 559
Joined: Tue Mar 27, 2007 1:29 am
Thanked: 5 times
Followed by:2 members

by Cybermusings » Tue May 15, 2007 10:05 am
A restaurant receives clean uniforms on May 3 and every 7 days thereafter. The restaurant receives clean linens on May 4 and every 5 days thereafter. On what date in May does the restaurant receive both clean uniforms and clean linens?
A. may 3
B. may 10
C. may 17
D. may 19
E. may 24

Uniforms - May 3, May 10, May 17, May 24, May 31
Linen - May 4, May 9, May 14, May 19, May 24, May 29
Hence May 24

Legendary Member
Posts: 559
Joined: Tue Mar 27, 2007 1:29 am
Thanked: 5 times
Followed by:2 members

by Cybermusings » Tue May 15, 2007 10:23 am
If y= x^2-5x+14 and z= x^2-x+2, what is the set of all values of x for which y=2z?
A. (-5)
B. (2)
C. (3)
D. (-2, 5)
E. (-5,2)

E??