How many paths are there from C to B, if every step must be up or to the right?
You have to go right 8 times and up 2 times. We can write this as RRRRRRRRUU. There are 10!/(8!*2!) ways to arrange it so the answer is 45
:D
You must go up 2 and right 8, so the answer is \(\binom{10}{2}=\boxed{45}\)
