Make the greatest and the smallest $$5$$ digits numbers using different digit in which $$5$$ appears at ten's place.
$$\textbf{Making the greatest and the smallest 5-digit numbers using different digits}$$
Digits are $$0, 1, 2, 3, 4, 5, 6, 7, 8, 9$$
$$5$$ always appear at ten's place = _ _ _ $$5$$ _
For greatest number place $$9$$ at the highest place value and then $$8$$ and $$7$$ and in units place $$6$$.
$$\textbf{Therefore the greatest number is 98756}$$
Now for smallest number take the digit $$1$$, as a number cannot start with $$0$$
Then write $$0$$ and $$2$$ in the next places and $$3$$ in units place.
$$\textbf{Therefore the smallest number is 10253}$$
$$\textbf{Hence, the greatest and least 5-digit numbers are 98756 and 10253 respectively}$$.