M srinivas
Last Activity: 7 Years ago
Let us take a 10*10 chessboard.
In this, A is at one end and B is at the other end of the big square ( 10*10 ).
So, if we take B only takes two left steps and one down step and A takes the remaining 8 right steps and 9 up steps.
so total no.of steps needed so that they can meet up are 10 horizontal steps and ten vertical steps.
so, if we select 10 steps out of these 20 then that should give the number of ways they can meet up beacuse if we select these 10 steps automatically reamining steps will be selected.
So answer would be 20C10.
(Illustrate the figure to get an idea of what I said above)