its simple...
You have....
1000! (otherwise known as 1000 factorial)...
your job is to find out.. how many 0's are at the end of this long crazy problem... and to be give time limit.. you have 1 minute to do it... thats all.. GO!!!
I can do this in 1 minute... so you can too..
2006-10-06 06:52:36 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
249
2006-10-06 06:58:12 · answer #1 · answered by captain2man 3 · 1⤊ 0⤋
The second answer above, 249, is the right one. And yes, it is a one-minute problem.
Each zero comes from a 5 and 2 in the prime factorization of 1000!, so where do these factors come from?
From each multiple of 10, of which there are 100.
From each multiple of 5, paired with a factor of 2 from some unused even number, of which there are also 100.
From each multiple of 25=5^2, since it contributes an additional factor of 5, along with some factor of 2. There are 40 of these.
From each multiple of 125=5^3, since it contributes yet another factor of 5. There are 8 of these.
From 625=5^4, since it contributes one more 5.
Add 'em all up and you get 249.
2006-10-06 07:29:51 · answer #2 · answered by James L 5 · 0⤊ 0⤋
btw 10-100 10 zeros
" 110-200 10
10*9=90 + 12 =102 zeros(12 from 910-1000)
2006-10-06 07:09:52 · answer #3 · answered by n nitant 3 · 0⤊ 0⤋
50
2006-10-06 06:56:14 · answer #4 · answered by joeyschiliro 2 · 0⤊ 0⤋
rote and involved
2006-10-06 07:01:12 · answer #5 · answered by openpsychy 6 · 0⤊ 0⤋