2007 Cyprus MO/Lyceum/Problem 28
Problem
The product of is an integer number whose last digits are zeros. How many zeros are there?
Solution
The number of zeros at the end of a number is determined by the number of 2's and 5's in its prime factorization.
There are 12 's and 19 's. Each pair adds a zero, but any extras don't count (in this case, the 7 extra 's).
See also
2007 Cyprus MO, Lyceum (Problems) | ||
Preceded by Problem 27 |
Followed by Problem 29 | |
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