Here's a thought. The probability of drawing an ace in the first week is 4 in 52.

If an ace is not drawn in the first week then the probability of drawing an ace in the second week is 4 in 51, 4 aces remain, but only 51 cards.

Therefore the probability ofnotdrawing an ace in the first two weeks is

Build on this idea, can you see a pattern as the weeks increase?