Suppose I am giving you a two wheeler,
It has one front wheel and one rear wheel,
Now I am giving you one more wheel (extra wheel)
So now total you have 3 wheels,
Each wheel can travel 5 kms and after that wheel will burst.
Then what will be the maximum distance that you can travel with this two wheeler.
Note :- You can interchange all 3 wheels with each other to travel longer distance.