If 25*24*23 ... 3 * 2 * 1 is expanded, how many zeros are there at the end of the answer?
is there some shortcut to solve this?
+128475 Here's the shortcut :
25*24*23* .....* 2 * 1 = 25!
Divide 25 / 5 and discard any remainders = 5
Divide 25 / 5^2 and discard any remainders = 25 / 25 = 1
Add the whole numbers = 5 + 1 = 6 trailing zeroes
Another example
300!
300 / 5 = 60
300/5^2 = 300/ 25 = 12
300/5^3 = 300/125 = 2 + 50/125
Add the whole numbers = 60 + 12 + 2 = 72 trailing zeroes
