Calculating the mean (with 5 random sample and the top 5 numbers) from 90 population

Hi all,

first time user and im hoping somewould could assist. I have a tricky question (for me anyway) and need to calculate the Mean/average.

OK here is the example

There are 90 people all earning various salaries.

The only info i have is 5 salaries chosen at random, but im also given the top 5 salaries.

I need to work out the mean of the 90 people, by only using the 5 random salaries and 5 of the top salaries provided.

Is this possible and can someone show me an easy way to calculate?

Thanks in advance

Is this all the problem states? Seems like there is something missing? How can one calculate the mean of 90 salaries given just 10 of the salaries?