You receive 10 letters, 5 of them come in red envelopes and 5 of them in blue envelopes. You randomly shuffle them and place them in a stack.

You receive 10 letters, 5 of them come in red envelopes and 5 of them in blue envelopes. You randomly shuffle them and place them in a stack.

Let A be the event that there is at least 1 blue envelope in the top three letters of the stack.

What is P(A)? (Your answer should be accurate to 3 decimal places.)