Time & Work, Chain Rule

A television service center can process 8 televisions in 18 minutes. How many televisions can it process in 3 hours at this rate? 

A, B and C each working alone can complete a job in 6, 8 and 12 days respectively. If all three of them work together to complete the job and earn $2340, what will be C's share of the earnings?

Worker P is 50% as efficient as worker Q. Worker R does half of the work done by P and Q together. If R alone does the work in 40 days, then P, Q and R together can do the work in -

A tap can fill a tank in 6 hours. After half the tank is filled three more similar taps are opened. What is the total time taken to fill the tank completely? 

Reza sells 500 shares in a company via a stock broker who charges a flat Tk. 20 commission rate on all transactions under Tk. 1000. His bank account is credited with Tk. 692 from the sale of the shares. What price were his shares sold at?

A ferry can travel twice as fast when empty as when it is full. It travels 20 miles with full load, spends 1 hour for unloading and returns to its original post empty. It took 11 hours to complete the journey. What is the speed of the ferry when it is empty?