Question 3
When the number
$$
N = 1^{1} \times 2^{2} \times 3^{3} \times \cdots \times 9^{9}
$$
is written as a decimal number, how many zeros does it end in?
$$
N = 1^{1} \times 2^{2} \times 3^{3} \times \cdots \times 9^{9}
$$
is written as a decimal number, how many zeros does it end in?