Question

The digits in the tens place and units place of a two digit number are $t$ and $u$ respectively. If $1$ is placed between them, what is the value of the three digit number so formed?

• A. $100u+t+10$
• B. $100t+10+u$
• C. $10t+u+1$
• D. $100t+10u+1$

Answer 1

The correct option is B $100t+10+u$

Let the number in one's place be $u$ and the number in ten's place be $10t$.

According the the question

$\Rightarrow 10t+1+u$

Hence now the 10t will become 100t as it will take hundred's digit place and 1 will become 10 as it will take ten's digit place.

Hence the value of 3 digit number will be $100t+10+u$.