A can do 50 % of the job in 16 days; B can do ¼ th of the job in 24 days. In how many days can they do ¾ th of the job working together?

A can do 50 % of the job in 16 days; B can do ¼ th of the job in 24 days. In how many days can they do ¾ th of the job working together?