Question

A train covers first 100 km in 4 hrs and next 200 km in 5 hrs. What is its average speed?

Answer 1

Answer:Let the speed in first case be S1

Let the speed in second case be S2

S1=100/4=25 km/hr.

S2=200/5=40 km/ hr.

AVG speed=(S1+S2)/2

=(25+40)/2

=65/2

=32.5km/hr.

Explanation:

Answer 2

Answer:

D1= 100Km                              D2=200Km

T1 = 4Hrs                                  T2=5Hrs

• Total distance = D1 + D2

                                 =100+200

                                 =300

• Total time = T1 + T2

                          =4+5

                          =9Hrs

• Avg. Speed = total distance /total  time

                             =300/9

                            =33.33Km/hr