You are living in the world of 2d graphs. You start at point **(0,0)**. Your friends' house is at coordinates **(10,10)**.You can only move either one step *RIGHT* or one step *UP* at a time. Can you find number of ways to reach your friends house?

**soln**

Easy?Hmm.Well the tricky(or is it?) part is, can you calculate the number of ways to reach the same destination if you have to make only even number of turns in your journey?

**soln**

Got asked this question in an interview, so I thought i would share it here ^_^