what are your numbers?!?

its 20% each time.

.20

.20

.20

.20

.20

.20

.20

.20

.20

this never changes

His math is suspect, but he has the right idea. While the percentage chance of success never changes the probability of continued failure does go down. On the first attempt the odds of success versus failure are 20%/80%, however the odds of success versus seven failures in a row is all but a coin flip - 20% chance of success versus 20.97% chance of seven failures. And the odds of success are actually better than that of eight failures 20%/16.78%