What is the probability that some node (either A, B, C or D) succeeds in slot 3?

What is the probability that some node (either A, B, C or D) succeeds in slot 4?

p(A succeeds in slot 3) = p(1-p) ^3

p(B succeeds in slot 3) = p(1-p) ^3

p(C succeeds in slot 3) = p(1-p) ^3

p(D succeeds in slot 3) = p(1-p) ^3

= 4p(1-p)^3

Same answer for slot 4?

Please tell me whether the answers are correct or not?

Zulfi.