Student: How many zeroes are there at the end of the number N, if N = 100! + 200! ?\nOptions:\n(A) 73\n(B) 49\n(C) 20\n(D) 48\n(E) 24.
Another student: Let's say, hmmm...

User
The number of zeroes at the end of 100! will be less than the number of zeroes at the end of 200!\nHence it would be sufficient to calculate the number of zeroes at the end of 100!\nNumber of zeroes = [100/5] + [100/25] + [100/125] = 20 + 4 + 0 = 24 Final answer: (E).
Assistant