Question

Write the greatest and the smallest $4$-digit numbers using four different digits with the condition that $5$occurs at ten's place.

Answer 1

to write the smallest number you need to write the numbers in increasing order like $1,2,3,4,5....$

but mention$5$ at tens place.

Smallest four digit number = $1253$

to write the Largest number you need to write the numbers in Decresing order like $9,8,7,6,5....$

Largest four digit number = $9857$

Hence, Smallest four digit number = $1253$,Largest four digit number = $9857$.