Answer:
$440
Explanation:
Given information:
- Emily spent 2/11 of her monthly salary on food.
- Then she spent 3/8 of the remaining amount on rent.
- Then she spent 1/9 of what still remained on books.
- Emily had $200 left after all these expenses.
Let "x" be Emily's monthly salary.
If she spent 2/11 of her monthly salary on food, the amount left of her monthly salary is:

She then spent 3/8 of the remaining amount on rent, so she had 5/8 left of the remaining amount:

She then spent 1/9 of what still remained on books, so she had 8/9 left of the remaining amount:

We are told that the amount she still had left is $200. Therefore:

To find Emily's monthly salary, solve the equation for x:

Therefore, Emily's monthly salary is $440.
We can check this by calculating her expenses.
Emily spent 2/11 of her monthly salary on food.


Therefore, Emily spent $80 on food, and had $360 remaining.
She then spent 3/8 of the remaining amount on rent:


Therefore, Emily spent $135 on food, and had $225 remaining.
She then spent 1/9 of the remaining amount on books:


Therefore, Emily spent $25 on books, and had $200 remaining.
Hence confirming that Emily's salary per month is $440.