A certain numberof persons can complete a work in 34 days working 9 hours a day. If the number of persons is decreased by 40%, then how many hours a day should the remaining persons work to complete the work in 51 days?
A car travelled 36 km at 6km/hr faster than the usual speed but it returned the same distance at 6kmph slower than the usual speed. If the total time taken by the car is 8 hrs. For how many hours does the car travelled at faster speed.