Question

# The two digit number ${\text{x}}$ is the digit at unit place and ${\text{y}}$ is the digit at unit place, then the number is :${\text{A}}.10y + x \\ {\text{B}}.10x + y \\ {\text{C}}.10y - x \\ {\text{D}}.10 - y \$

Hint â€“ Use the concept of ones and tens and make an equation, take an example of any two digit number.
It is a two digit number ${\text{x}}$ is the digit at unit place and ${\text{y}}$ is the digit at tens place .
Let us take an example of a two digit number $51$ so here $\,1$ is at the unit place and ${\text{5}}$ is digit at the tense place . So here,
$x = 1\,\,\& \,\,y = 5$ â€¦â€¦(i)
We can write $51$ as
$51 = 50 + 1 = 10(5) + 1$
We can write the above equation as $10y + x$ â€¦â€¦(From (i))
Hence the correct option is A.
Note â€“ In these types of questions we must have to know that, just left of decimal point is one place and left of one's place is a tens place. We should know that when we write the numbers of all these places in addition/subtraction then these numbers get multiplied by the number of their respective names, then aon adding/subtracting we will get the number .