factor questoin
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Source: Beat The GMAT — Problem Solving |
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sudhir3127
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parallel_chase
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Even I think the answer is 34.
(3!*4!)!= 144!
we have to find the number of 5's and 2's to determine the consecutive 0's
multiples of 2 = 72
multiples of 5 = 28
We just have to concentrate on 5's since we have enough number of 2's
Therefore number of 5's will be the number of consecutive 0's
25=5*5 (one five is already counted, we just have to add 1 more 5)
50=5*5*2 (one five is already counted, we just have to add 1 more 5)
75=5*5*3 (one five is already counted, we just have to add 1 more 5)
100=5*5*4(one five is already counted, we just have to add 1 more 5)
125=5*5*5 (one five is already counted we just have to add 2 more 5's)
Therefore total number would be =28+1+1+1+1+2=34
whats the OA?
(3!*4!)!= 144!
we have to find the number of 5's and 2's to determine the consecutive 0's
multiples of 2 = 72
multiples of 5 = 28
We just have to concentrate on 5's since we have enough number of 2's
Therefore number of 5's will be the number of consecutive 0's
25=5*5 (one five is already counted, we just have to add 1 more 5)
50=5*5*2 (one five is already counted, we just have to add 1 more 5)
75=5*5*3 (one five is already counted, we just have to add 1 more 5)
100=5*5*4(one five is already counted, we just have to add 1 more 5)
125=5*5*5 (one five is already counted we just have to add 2 more 5's)
Therefore total number would be =28+1+1+1+1+2=34
whats the OA?
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sudhir3127
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good work chase...
just an improvement.. i dont think we need to look for 2's as well
the method can be
144/5 + 144/25 +144/125 = 34..
thats it !!!
just an improvement.. i dont think we need to look for 2's as well
the method can be
144/5 + 144/25 +144/125 = 34..
thats it !!!












