A small manufacturing company has rated

80% of its employees as satisfactory and 20% as unsatisfactory . Personnel records show that 75% of the satisfactory workers had previous work experience in the job they are now doing, while 30% of the unsatisfactory workers had no work experience in the job they are now doing. If a person who has had previous work experience is hired, what is the approximate probability that this person will be an unsatisfactory employee?

I just need the ratio and the process of getting the answer Thanks!