To find number of zeroes at the end of any number factorial,
you have to
count number of zeroes i.e. multiplication by 10 and 5 in the series.
e.g. 10! number of 5 and 10 there are 1 + 1 = 2 so number of zeroes = 2
in case of 25! number of 5 are, 5, 15, 25 (contains 2 fives)
and number of zeroes in 10 and 20
so total number of zeroes at the end in the product is 4 + 2 = 6
But in longer series it is difficult to count number of zeroes and fives
to find
divide the last number i.e. 25 by 5 and go on dividing the quotient by5
till the quotient...
Friday, June 29, 2012
PUZZELS
This
problem is actually damn hard, I don't know why I put it first.
You are
given a set of scales and 12
marbles. The scales are of the old balance variety. That is, a small
dish hangs from each end of a rod that is balanced in the middle. The
device enables you to conclude either that the contents of the dishes
weigh the same or that the dish that falls lower has heavier contents
than the other.
The
12 marbles appear to...
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