Math miscellaneousHard
Question
Number of possible values of n such that n! has exactly 20 zeroes at the end is equal to -
Options
A.4
B.5
C.6
D.7
Solution
Let number of zeroes = x = 
⇒ x <
(∵ [x] ≤ x)
⇒ x <
⇒ n > 80
If n = 80, x =
If n = 85, x =
If n = 90, x =
⇒ n ∈ {85, 86, 87, 88, 89}
⇒ x <
(∵ [x] ≤ x)⇒ x <
⇒ n > 80
If n = 80, x =
If n = 85, x =
If n = 90, x =
⇒ n ∈ {85, 86, 87, 88, 89}
Create a free account to view solution
View Solution FreeMore Math miscellaneous Questions
The average marks of boys in a class is 52 and that of girls is 42. The average marks of boys and girls combined is 50. ...If f(x) = dt, 0 , then f′(x) is -...Let ƒ′ (x) = for all x ∈ with = 0. If m ≤dx ≤ M, then the possible values of m and M are...dx is equal to...3λ + 2μ = 0 then...