Maximum possible Length

This topic has expert replies
User avatar
Senior | Next Rank: 100 Posts
Posts: 56
Joined: Wed Sep 01, 2010 10:04 am
Thanked: 1 times
Followed by:20 members

Maximum possible Length

by Akansha » Tue May 31, 2011 6:17 pm
5 pieces of wood have an average length of 124cm and median length of
140cm. what is the maximum possible length of the shortest piece of wood?
a. 90
b. 100
c. 110
d. 130
e. 140

OA is B
Source: — Problem Solving |

User avatar
Legendary Member
Posts: 965
Joined: Thu Jan 28, 2010 12:52 am
Thanked: 156 times
Followed by:34 members
GMAT Score:720

by vineeshp » Tue May 31, 2011 6:28 pm
Total length of 5 pieces is 5 * 124 = 620.
To get maximum for shortest piece, we must max out all other pieces.

So let the longer three pieces be 140 each.
So the lengths are
a , b , 140, 140, 140.

Total length is 620
a + b + 140 + 140 + 140 = 620
a + b = 200.
Now to get the max length of the shortest piece we must max out these values and the way to do it is to make both lengths equal. that is a = b.
a + b = 200 -> a=100, b=100.

There are other combinations possible, but any other combination you take, one length will go down below 100 and that will become the shortest piece. So 100 is maximum possible length of the shortest piece.
Vineesh,
Just telling you what I know and think. I am not the expert. :)

User avatar
Legendary Member
Posts: 1309
Joined: Mon Apr 04, 2011 5:34 am
Location: India
Thanked: 310 times
Followed by:123 members
GMAT Score:750

by cans » Tue May 31, 2011 10:30 pm
mean = 124 and thus sum of 5 pieces = 124*5 = 620
let lengths in ascending order = a,b,c,d,e
given c=140, a+b+c+d+e = 620
to maximize a, minimize b,d,e. d and e should be at least equal to c and thus min possible value of d & e is 140
thus a+b+140*3=620
or a+b=200
now b>=a and to maximize a, let b=a and thus a=100
IMO B