Explanation:
The probability of Benjamin winning any competition is 8/10, which means the probability of him not winning any competition is 2/10.
The probability of winning at least one competition can be calculated using the complement rule, which states that the probability of an event happening is equal to 1 minus the probability of the event not happening.
So, the probability of Benjamin winning at least one competition can be calculated as:
1 - probability of not winning any competition= 1 - (2/10)^10 (since he is competing in 10 competitions)
= 1 - 0.0000001024= 0.9999998976Therefore, the probability of Benjamin winning at least one competition is approximately 0.9999998976 or almost certain.