Cost of 4 pens, 6 note books and 9 files is Rs 305. Cost of 3 pens, 4 notebooks and 2 files is Rs 145. What is the cost (in Rs) of 5 pens, 8 notebooks and 16 files?
After excluding stoppages, the speed of a bus is 60 kmph and after including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?