Question

In a 2 digit number the digit of unit and tens place are x and y respectively. What are the numbers?
a: xy
b: yx
c: 10 x + y
d: 10 y + x​

Answer 1

Given: In a $2$digit number, the digit of unit and tens place are $x$and$y$.

We have to find the numbers.

As we know that we start from the unit place from the right side then tens and then thousand on the left side.

As $x$is the unit place holder and $y$is the tens place holder in the given problem.

So, we need to keep $y$to the left of$x$.

We are solving in the following way:

Suppose our number is$53$. It has $3$at units digit and $5$as the tens digit

So $53$can be written as $10$×$5$+$3.$

As we know that dividend=divisor×quotient+remainder

$\therefore xy=10\times y+x$

Hence, option d) is the correct answer.

Answer 2

To find : $2$ digit number =s .

Given : unit and tens place digits are $x$ and $y$ respectively.

Solution :

• While writing numbers we write numbers from right to tens starting from units place then tens , hundreds place and so on .
• We are given that $x$ is digit at units place and $y$ is a digit at tens place .  
• Therefore , as wee know that digit at tens  place is multiple of $10$ while digit at unit place is multiple of $1$.

• For example , let us consider number $25$ we can write $25$  as $( 20 + 5 =2\times 10 + 5)$ here we see that $2$ is ,multiple of $10$ while 5 is multiple of $1$ .
• Similarly, we can say that $y$ is multiple of $10$ and $x$ is multiple of $1$. Hence , we can write as $10y + x$.

Hence , numbers are $10y + x$.