John’s salary after doubling in 10 years is $ 2x
Solution:
It is given to us that John worked at a job for 10 years.
He started working at the job with a salary of $x.
After 10 years the salary has been doubled.
We have been asked to find John’s salary now after doubling.
To find John’s salary after 10 years we need to do the following.
Salary after 10 years = Salary before 10 years
2

Therefore, John’s salary after doubling in 10 years is $2x