The largest value of n, for which 40n divides 60!, is
- 14
- 13
- 11
- 12
Answer
(1) 14
Solution
40 = 23 5
Exponent of 2 in 60! = [ 602 ] + [ 604 ] + [ 608 ] + [ 6016 ] + [ 6032 ]
= 30 + 15 + 7 + 3 + 1 = 56
⇒ highest power of 23 dividing 60! is (23)18, since [ 563 ] = 18
Exponent of 5 in 60! = [ 605 ] + [ 6025 ] = 12 + 2 = 14
∴ Largest n = (18, 14) = 14
Answer: (1)