If the probability of event A is 60% (i.e. 0.6), then the probability
of four consecutive A events is:

0.6 * 0.6 * 0.6 * 0.6 = 0.1296 or 12.96%

If the probability of event B is 40%, then the probability of four
successive B events is:

0.4 * 0.4 * 0.4 * 0.4 which is 0.0256 or 2.56%

So, just multiply the probabilities for each successive event.

Hope this helps.

Pete