Final answer:
The probability that none of the three clowns are funny is 21.6%.
Step-by-step explanation:
The probability that none of the three clowns are funny can be calculated using the concept of independent events. Since each clown encounter is independent of the others and has a 60% chance of not being funny, the probability of none of them being funny can be found by multiplying the individual probabilities:
P(None of the clowns are funny) = 0.6 x 0.6 x 0.6 = 0.216 or 21.6%