A, B and C can do a job working alone in 50, 75 and 20 days respectively. They all work together for 4 days, then C quits. How many days will A and B take to finish the rest of the job?
A cloth merchant has announced 25% rebate in prices. If one needs to have a rebate of Rs. 40, then how many metres of cloth costing Rs. 32 per metre he should purchase