a car moves from A to B covering a distance of 1000km it covers the first 300km at 60km/h the next 400km at 80 km /h at what speed it should it cover the remaining distance so that achieve an average speed of 70km/h?
Now Jhanvi, you are asking the same question over and over with slight changes.
Figure out the time for each leg of your course.
Figure out the total time by adding the times for each leg.
Divide the total distance by the total time. That is your average speed.