Author 
Message 
GMAT Instructor
Joined: 04 Jul 2006
Posts: 1262
Location: Madrid

Upon melting, ice loses 8% of its volume. Ice cubes, the [#permalink]
Show Tags
26 Jul 2006, 04:32
Question Stats:
0% (00:00) correct
0% (00:00) wrong based on 0 sessions
HideShow timer Statistics
This topic is locked. If you want to discuss this question please repost it in the respective forum.
Upon melting, ice loses 8% of its volume. Ice cubes, the edges of which all measure 2 cm, are added to a jug containing 5 L, or 5,000 cubic centimetres of hot water. How many ice cubes were added?
(1) When the ice cubes melt, the jug contains between 5.98 L and 6.02 L of cold water.
(2) The number of ice cubes added is an even number.



Manager
Joined: 21 Jul 2006
Posts: 82

Re: DS: Ice cubes [#permalink]
Show Tags
26 Jul 2006, 08:25
kevincan wrote: Upon melting, ice loses 8% of its volume. Ice cubes, the edges of which all measure 2 cm, are added to a jug containing 5 L, or 5,000 cubic centimetres of hot water. How many ice cubes were added?
(1) When the ice cubes melt, the jug contains between 5.98 L and 6.02 L of cold water. (2) The number of ice cubes added is an even number.
Volume of the Cube = 8 cubic cm
Volume of water added if cube melts = 6.8 cubic cm.
5000 + n*6.8 = 5980 n =14
5000+ n*6.8 = 6020 n =15
From St1. & St2 its 14



CEO
Joined: 20 Nov 2005
Posts: 2894
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD  Class of 2008

E
Let x = number of ice cubes addded
Volume before ice cubes started meting = B = 8x + 5000
Volume after ice cubes melted = A = 7.36x + 5000
St1: 5980 <A < 6020
i.e 980 < 7.36x < 1020
x coul dbe anything between 134 and 138 (Both inclusive.)
St2: Clearly INSUFF
Combined:
x could be 134, 136 or 138. : INSUFF
_________________
SAID BUSINESS SCHOOL, OXFORD  MBA CLASS OF 2008



GMAT Instructor
Joined: 04 Jul 2006
Posts: 1262
Location: Madrid

I know you're a mighty calculator, but how can we conclude that the answer is indeed E without so much calculating?



CEO
Joined: 20 Nov 2005
Posts: 2894
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD  Class of 2008

kevincan wrote: I know you're a mighty calculator, but how can we conclude that the answer is indeed E without so much calculating?
I don't know the trick but I did a division of 98000/736 and 102000/736 and came up with 134 and 138. This is not a big calculation. The whole question took around 3 minutes.
_________________
SAID BUSINESS SCHOOL, OXFORD  MBA CLASS OF 2008



Director
Joined: 28 Dec 2005
Posts: 752

Re: DS: Ice cubes [#permalink]
Show Tags
26 Jul 2006, 14:40
kevincan wrote: Upon melting, ice loses 8% of its volume. Ice cubes, the edges of which all measure 2 cm, are added to a jug containing 5 L, or 5,000 cubic centimetres of hot water. How many ice cubes were added?
(1) When the ice cubes melt, the jug contains between 5.98 L and 6.02 L of cold water. (2) The number of ice cubes added is an even number.
total volume before the cubes melt = 8n + 5000
total volume after the cubes melt = 8.(0.92)n + 5000 = 7.36n+ 5000
5980<7.36n+5000<6020
=>
980<7.36n<6020
133.something < n < 138.something....
A is insuff
B is insuff
Combining, n could be 134, 136,138....insuff so E



GMAT Instructor
Joined: 04 Jul 2006
Posts: 1262
Location: Madrid

Great! E is the OA, but we could do with a better explanation!
Hint: How many cubic centimeters are there between 5.98L and 6.02L?



Manager
Joined: 21 Jul 2006
Posts: 82

Re: DS: Ice cubes [#permalink]
Show Tags
26 Jul 2006, 17:09
ghantark wrote: kevincan wrote: Upon melting, ice loses 8% of its volume. Ice cubes, the edges of which all measure 2 cm, are added to a jug containing 5 L, or 5,000 cubic centimetres of hot water. How many ice cubes were added?
(1) When the ice cubes melt, the jug contains between 5.98 L and 6.02 L of cold water. (2) The number of ice cubes added is an even number. Volume of the Cube = 8 cubic cm Volume of water added if cube melts = 6.8 cubic cm. 5000 + n*6.8 = 5980 n =14 5000+ n*6.8 = 6020 n =15 From St1. & St2 its 14
my bad. stupid calculations....pls ignore my response.
thx



Senior Manager
Joined: 12 Mar 2006
Posts: 365
Schools: Kellogg School of Management

kevincan wrote: Great! E is the OA, but we could do with a better explanation!
Hint: How many cubic centimeters are there between 5.98L and 6.02L?
0.04/0.92 = n*8e3 => n > 5 which means there will be atleast 5 integer values for the number of cubes in the range specified....
yes we need to keep looking for shortcuts....nice one kevin..



Intern
Joined: 01 Jul 2006
Posts: 19

Upon melting, ice loses 8% of its volume. Ice cubes, the edges of which all measure 2 cm, are added to a jug containing 5 L, or 5,000 cubic centimetres of hot water. How many ice cubes were added?
(1) When the ice cubes melt, the jug contains between 5.98 L and 6.02 L of cold water.
(2) The number of ice cubes added is an even number.
range of approx = 6.02  5.98 = 0.04L = 40 cubic cm..
volume of one cube = approx 7.2 cubic cm.. ( 2^3 * 92%)
statement 1  not sufficient , range of approximation could vary the results from 1 to 5 additional cubes
statement 2  not sufficicent  range of approx could vary the results between 2 or 4 additional cubes
together not sufficient
hence E










