What is the probability that the first card is an ace given that the 15th card is an ace 
Cards are drawn one at a time, without replacement, from a deck of 52
  playing cards. What is the probability that the first card drawn is an
  ace, given that the 15th card is an ace?

I have trouble calculating the probability of seeing aces on the first and the 15th draws and the probability of seeing $i$ aces in the first 14th draws, $i=0,1,2,3$. Any hint is much appreciated, thanks a lot!

Hint:  Take one ace out of the deck and put it in position $15$.  Then you have how many aces left out of how many cards left?
