In a class of 39 students there are 26 girls. The average weight of these girls is 42 Kgs and average weight of the full class is 48 kgs. What is the average weight (in kgs) of the boys of the class?
A can do 75% of a job in 9 days and B can do half of the job in 8 days. If they work on it together, then in how many days can they do half of the job?