Question

The sum of the smallest $4-\mathrm{digit}$ number using only one digit and the greatest $4-\mathrm{digit}$ number is

• A. $10999$
• B. $10000$
• C. $11110$
• D. $11011$

Answer 1

The correct option is C

$11110$

Explanation for the correct option.

Option $C$: $11110$

The increasing order of the whole number is $0,1,2,3,4,5,6,7,8,9$.

The smallest $4-\mathrm{digit}$ number using only one digit cannot be possible by taking $0$ five times as it will result in $0$.

So, we will take the next number from the series which is $1$.

Therefore, the smallest $4-\mathrm{digit}$ number using only one digit is $1111$.

The greatest $4-\mathrm{digit}$ number is $9999$.

Therefore, the sum of the smallest $4-\mathrm{digit}$ number using only one digit and the greatest $4-\mathrm{digit}$ number$=1111+9999$

$=11,110$.

Hence, the correct option is option $C$.