BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

grouping

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 135
Joined: Mon Oct 03, 2011 6:54 am
Followed by:4 members

grouping

by nidhis.1408 » Mon Jul 16, 2012 8:53 am
Orange Computers is breaking up its conference attendees into groups. Each group must have exactly one person from Division A, two people from Division B, and three people from Division C. There are 20 people from Division A, 30 people from Division B, and 40 people from Division C at the conference. What is the smallest number of people who will not be able to be assigned to a group?
Top
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 141
Joined: Tue Oct 04, 2011 5:17 am
Thanked: 25 times

by coolhabhi » Mon Jul 16, 2012 10:57 am
nidhis.1408 wrote:Orange Computers is breaking up its conference attendees into groups. Each group must have exactly one person from Division A, two people from Division B, and three people from Division C. There are 20 people from Division A, 30 people from Division B, and 40 people from Division C at the conference. What is the smallest number of people who will not be able to be assigned to a group?
IMO : 12

what is the OA??
Top
Master | Next Rank: 500 Posts
Posts: 135
Joined: Mon Oct 03, 2011 6:54 am
Followed by:4 members

by nidhis.1408 » Mon Jul 16, 2012 11:53 am
20 for division A
30/2=15 for division B
40/3= 13 for division C, 1 left

C is the limiting factor

for the group- 13 A (20-13)=7 left
2*13=26 B (30-26)= 4 left
1 left in C

therefore the smallest number of people who will not be able to join a group will be= 7+4+1= 12

Its a manhattan problem.
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 130
Joined: Fri Apr 20, 2012 8:13 am
Location: Toronto, Ontario
Thanked: 16 times
Followed by:4 members
GMAT Score:650

by tisrar02 » Tue Jul 17, 2012 7:46 pm
Here's how I do these types of problems:

I start off with division C and look at Division A as well. So if Division A has 15 people, Division C has to have 45 people. 15*3. Thats wrong. Even less is needed so we go down to 14 and realize that 14*3 is 42. Still too high but now were making progress and you get the feel of the pattern so you catch that 13 is the correct number. You quickly verify that B will have the correct amount of people and it doesn't go over and then you calculate how many people are not listed.

A- 13= 7 people are left out
B - 13*2= 26--> 4 people are left out
C- 13*3= 39--> 1 person is left out


7+4+1= 12

Thanks
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 308
Joined: Thu Mar 29, 2012 12:51 am
Thanked: 16 times
Followed by:3 members

by Lifetron » Sat Jul 21, 2012 6:24 am
It is more like

The number of groups = x

Total no. of people listed to form groups= x+2x+3x

Max 3x = 39, groups = 13

So,
13 -> 7 left
26 -> 4 left
39 -> 1 left

Total = 12
Top
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Sun Aug 26, 2012 8:05 am

by chibimoon9 » Sun Nov 25, 2012 11:25 pm
Could you explain for me how you got Max 3x = 39 please

thank you
Top
Post new topic Post Reply
• Page 1 of 1