John can paint his home exterior in 16 hours alone. if john starts painting 2 hours before pattie joins him, they can finish the job in 8 mroe hours. how long would it take pattie if she painted the home exterior alone?

a) 18 hours
b) 20 hours
c)21 1/3 hours
d)20.5 hours
e) none of the above

explain your answer. it would be much appreciated.