On a straight road XY, 100 m long, five heavy stones are placed 2 m apart beginning at the end X. A worker, starting at X, has to transport all the stones to Y, by carrying only one stone at a time. The minimum distance he has to travel is

The minimum distance to be walked is 100 (onward)+ 98 (return) + 98 (onward) + 96 (return) + 96( onward) + 94(return) + 94(onward) + 92(return) + 92(onward) = 860 metres

x--------------------100m--------------------------y (Given XY=100 m)

now stones are placed at beginning of X and how many stones ? 5

X---------------------------------------------------------------------------Y 

*1------*2--------*3--------*4--------*5---------------------------------Y (Consider * As stone)(*1 =first Stone,*2=Second Stone,*3=Third Stone...so on )

     2m      2m        2m        2m        92 m                                   (Stones Are separated by 2m)

1) Truck start and carry *1 stone and move towards Y, 

------------------------------------------------------------------------------->

  he traveled 100 m

2) He  moves from Y and travel upto *2 stone and carry *2 stone and move towards Y

          *2<---------------------------------------------------------------------

          *2---------------------------------------------------------------------->

   he traveled 98+98

3)He moves from Y and travel upto *3 stone and carry *3 stone and move towards Y

                          *3<---------------------------------------------------------

                          *3---------------------------------------------------------->

   he traveled 96+96

4)Moves from Y and travel upto *4 stone ,carry *4 stone and move towards Y end

                                           *4<-------------------------------------------

                                           *4-------------------------------------------->

   he traveled 94+94

5) Last stone *5 to carry,He moves from Y to towards *5 Stone then carry *5 stone and move towards Y

                                                          *5<--------------------------------

                                                          *5--------------------------------->

  he traveled 92+92

Total Distance Covered 100+98+98+96+96+94+94+92+92= 2(50+98+96+94+92)= 2 *430=860 m