Board Thread:News and Announcements/@comment-15992106-20130904013742/@comment-13957855-20130906223419

The easiest way to calculate the probability of at least one successful attempt out of 'n' attempts is to calculate the probability of _no_ successful attempts. In the case we are talking about, the original probability of breeding a ghast on one attempt is 1%. With a 500% increase, the temporary odds are 6% for one try, or odds of 94% of failure in one attempt. To calculate the odds of failing 8 times in 8 attempts, we would calculate (.94)^8, which is .61 to the nearest hundredth. Thus, the odds of _at least_ one success out of 8 tries is 1-.61, or about 40%. This is how I would have shown a student to work this particular problem last time I taught probability.