The probability that the first person draws the red label is 1/5.
Probability that the second person draws a red label: if the first person draws a red label, it is 0; If the first person doesn't draw, it is 1/4, then the probability that the second person draws the red mark is (1-1/5) *1/4 =1.
In the same way, it can be concluded that the probability of others drawing a red ticket is also one in five.