Question

Usha walked at the speed of 7/
3

km per hour for 2 hours and

then at the speed of
3/2 km per hour for next 2 hours. Find the

total distance walked by Usha in 4 hours

Answer 1

Distance 1=7/3*2=14/3 km
Distance 2=3/2*2=6/2 km
LCM=6
D1=14/3*2/2=28/6km
D2=6/2*3/3=18/6km
Total Distance=D1+D2
TD=28/6+18/6
TD=46/6 km=7 whole 4/6 km

Answer 2

Speed of Usha in first two hours = 7/3 km/h
Distance traveled by Usha in first two hours = Speed * time
                                                                      = 7/3 * 2
                                                                      = 14/3 km
                                                                      = 4.667 km
                                                                      = nearly 4.7 km

Speed of Usha in next two hours = 3/2 km/h
Distance traveled by Usha in next 2 hours = 3/2*2
                                                                   = 3 km

Total distance traveled by Usha in 4 hours = 4.7 + 3
                                                                    =  7.7 km (nearly)

Hope this helps you.