PROBLEM LINK:Author and Editorialist : Dhruv Mahajan DIFFICULTYSimple EXPLANATION:Average Speed is Not (u+v)/2. But it is (total distance covered)/(total time taken). Let distance from A to B is 'd', then time taken from A to B is d/u. And distance between B to A will also remain 'd', hence time taken from B to A is d/v. Total distance covered in the journey is 2d. Hence average speed will be (total distance covered)/(total time taken), which is (2d)/(d/u+d/v) which is equal to 2uv/(u+v). Remember if u=0 and v=0 then avg speed will also be zero. SOLUTIONS
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asked 16 Oct '15, 18:26

Why was this contest not listed in the Contests section? answered 16 Oct '15, 18:36
