I was trying to finish the problem 3 after the contest because I was curious about the answer

Here is the question:

Alice plays the following game, loosely based on the card game "21".

Alice starts with 0 points, and draws numbers while she has less than K points. During each draw, she gains an integer number of points randomly from the range [1, W], where W is an integer. Each draw is independent and the outcomes have equal probabilities.

Alice stops drawing numbers when she gets K or more points. What is the probability that she has N or less points?

I have my test case as N = 4, K = 2, W = 6

All the combinations should be 2, 3, 4, 5, 6, 1+1, 1+2, 1+3, 1+4, 1+5, 1+6, which is 11 of them.
The ones <= N are 2, 3, 4, 1+1, 1+2, 1+3

So the answer should be 6/11, which is 0.54545. However, the expected answer is 0.58333. Can someone tell me why? I really to know it.