Question

A bus runs for 3 hours at a speed of 45 km per hour and for the next 2 hours at a speed of 50 km per hour. Find the average speed of the bus for the 5 hours journey.

Answer 1

Avg speed = (total distance covered)/total time

Savg = ((45x3)+(50x2))/(3+2)
= (135+100)/5
= 235/5
= 47 km/hr

Answer 2

                                         ☺☺☺

Sol : Distance covered by bus in first 3 hours = Speed x Time
                                                                        
                                                                         = 45 x 3 km = 135 km.

Distance covered by bus in next 2 hours = Speed x Time

                                                                 = 50 x 2 km = 100 km.

Total distance covered by bus = 135 km + 100 km = 235 km.

Total time taken to cover 235 km = 5 hours.

                             Total distance covered by body
Average speed = -------------------------------------------
                                    Total time taken


                            235 km
Average speed = -------------
                               5 h

Average speed = 47 km/h.

          
                                     ☺☺☺