X, Y and Z can do a piece of work in 30, 40 and 50 days respectively. All three of them began the work together but Y left 4 days before completion of the work. In how many days was the work completed?
Smita can finish a work in 12 days and Sam can finish the same work in 9 days. After working together for 4 days they both leave the job. What is the fraction of unfinished work?
The original price of a TV set is Rs. 6,000. If the price is discounted by 20% and then raised by 10% for service contract, the price charged by the shopkeeper is