Question: can someone please show me the workings for the following...

Can someone please show me the workings for the following question:

 

Mandatory drug testing

In July 2011, the state of Florida started testing all welfare recipients for the use of illegal drugs. Statistics suggest that some 8% of adult Floridians use illegal drugs; let us assume that this is true for welfare recipients as well. Imagine that the drug test is 90% accurate, meaning that it gives the correct response in nine cases out of 10.
c) What is the probability that a randomly selected Floridian welfare recipient has a positive test.

The answer is 0.164 but I'd like to see the workings to understand how to get the answer