how many zeroes are there at the end of the number n , if n = 90 ! + 180 ! ?
"the number of zeroes at the end of 90 ! will be less than the number of zeroes at the end of 180 ! hence it is sufficient to calculate the number of zeroes at the end of 90 ! the number of zeroes = [ 90 / 5 ] + [ 90 / 25 ] + [ 90 / 125 ] = 18 + 3 + 0 = 21 the answer is c ."
add(divide(90, add(const_4, const_1)), const_2)