How many zeroes are there at the end of the number N, if N = 70! + 140! ?	Pick one.
A) 8	B) 12	C) 16	D) 20	E) 24

Rationale: "the number of zeroes at the end of 70 ! will be less than the number of zeroes at the end of 140 ! hence it is sufficient to calculate the number of zeroes at the end of 70 ! the number of zeroes = [ 70 / 5 ] + [ 70 / 25 ] + [ 70 / 125 ] = 14 + 2 + 0 = 16 the answer is c ."
Answer: C