In a row of $40$ girls, Kavya is sitting $22\text{nd}$ from the left end and Maya is sitting $20\text{th}$ from the right end. If they interchange their positions, what will be Kavya's new position from the left end?

To find Kavya's new position from the left end, we first note that after interchanging, Kavya occupies Maya's original position.
* Total number of girls = $40$
* Maya's original position from the right end = $20$

We can find Maya's original position from the left end using the formula:

$$\text{Position from Left}=\text{Total}-\text{Position from Right}+1$$

$$\text{Maya’s Position from Left}=40-20+1=21\text{st}$$

Since Kavya moves to Maya's place, Kavya's new position from the left end will be exactly the same as Maya's original position from the left end, which is $21\text{st}$.