Question

The first twenty natural numbers from $1to20$ are written next to each other to form a $31-$digit number $N=1234567891011121314151617181920$. What is the remainder when this number is divided by $16$

• A. $0$
• B. $4$
• C. $7$
• D. $9$

Answer 1

The correct option is A $0$

The given number is

$1234567891011121314151617181920$.

$\Rightarrow$ Divisibility rule of $16$: The number formed by the last four digits in the given number must be divisible by $16$.

$\Rightarrow$ The last four digits of a given number is $1920$

$\Rightarrow$ $1920$ is divisible by $16$, so given number is divisible by $16$.

$\therefore$ The required remainder is $0$.