Elementary Number Property

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Elementary Number Property

by Aman verma » Sun Feb 07, 2010 3:22 am
Q: Nancy wanted to cut a cubical cake into 120 identical pieces applying minimum number of 'n' cuts. Later on she realised that she had to cut this cake into maximum number of identical pieces i.e 125 pieces. The number of cuts she now applies is :

a) n

b) n+5

c) n+ 1

d) n+ 3

e) n+ 2
Source: — Problem Solving |

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by thephoenix » Sun Feb 07, 2010 3:29 am
imo n+5

for 120 pieces no of cuts=119=n
for 125 pieces no of cuts=124=n+5

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by ajith » Sun Feb 07, 2010 3:31 am
Aman verma wrote:Q: Nancy wanted to cut a cubical cake into 120 identical pieces applying minimum number of 'n' cuts. Later on she realised that she had to cut this cake into maximum number of identical pieces i.e 125 pieces. The number of cuts she now applies is :

a) n

b) n+5

c) n+ 1

d) n+ 3

e) n+ 2
To cut the cake into 120 =4*5*6 the minimum no of cuts = 12 (3 cuts along one side, 4 cuts on the adjacent side and 5 cuts along the height) 12 is the minimum and any other way will have more cuts
n=12

To cut the cake into 125 =5*5*5 the minimum no of cuts required = 12 (4+4+4)
=n

A, IMO
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by sumanr84 » Sun Feb 07, 2010 3:44 am
It seems to me not a GMAT Q but a math puzzle..

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by Aman verma » Mon Feb 08, 2010 5:26 am
Solution: 120 =4X5X6 (since minimum number of cuts are possible only when all the three factors are very close)

Again 125 = 5X5X5

But since 4+5+6 = 5+5+5=15 ,hence the same number of cuts are required as previously.Hence n number of cuts are required to get 125 identical pieces.