Question

Sumit drives his car at a constant rate of 40 Km/h for one hour and then at a constant rate of 60 Km/h for one hour. Find his average speed.

Answer 1

There is a little trick for this . From This trick you can do these type of sum in 30 sec

The trick is

$(2v1v2) \div (v1 + v2)$
Here it is
( 2×40×60 ) / ( 60 +40)
On solving u will get ,
48m/s(Ans)

Answer 2

average speed = 40+60/2
=50kmph