A number theory problem by sameer pimparkhede
Number Theory
Level
2
How many zeros are there at the end of 400!
The answer is 99.
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1 solution
To find the number of 0's we need to find the power of 5 in 400!.
[ 5 4 0 0 ] + [ 2 5 4 0 0 ] + [ 1 2 5 4 0 0 ]
8 0 + 1 6 + 3 = 9 9