Question 115
If $m!$ ends with exactly $n$ zeros, we say $n$ is the tail of the factorial $m!$. Look at the examples and answer: - $5! = 5 \times 4 \times 3 \times 2 \times 1 = 120$, ends at a zero, so the tail of the factorial $5!$ é $1$;
- $10! = 3628800$, ends in two zeros, then the tail of the factorial $10!$ is equal to $2$.
a) what are the tails of the factorials of $20!$ e $25!$?
b) what is the digit of the dozens of $7! + 8! + 9! + \ldots + 2018!$?
c) Some $m!$ has a factorial tail equal to $5$?
d) What is the factorial tail of $2018!$ (two thousand and eighteen factorial)?
e) How many positive integers smaller than $2018$ Are not factorial tail?
- $10! = 3628800$, ends in two zeros, then the tail of the factorial $10!$ is equal to $2$.
a) what are the tails of the factorials of $20!$ e $25!$?
b) what is the digit of the dozens of $7! + 8! + 9! + \ldots + 2018!$?
c) Some $m!$ has a factorial tail equal to $5$?
d) What is the factorial tail of $2018!$ (two thousand and eighteen factorial)?
e) How many positive integers smaller than $2018$ Are not factorial tail?