Question

If the square of a number ends with 10 zeroes, how many zeroes will the number have ?

Answer 1

We know that if a number ends with n zeros

Then its square will have 2n zeroes

Conversely, if square of a number have 2n zeros at their ends then the number will have n zeroes

$\because$ The square of a number ends 10 zeroes, then the number will have $\frac{10}{2}=5$ zeroes