A restaurant is giving away three different toys with each child's meal. What is the probability of getting all the toys in purchasing five meals?
2 Answers
Hint: Sufficient Condition for getting all 3 kinds of toys in 5 meals is that no single kind of toy appears 3 times or more.
Choose any three space for $ toy_1 , toy_2 $ and $ toy_3 $ in $ \binom{5}{3} $ ways. And fill the 2 blank space with any possibility with $ 3^2 $ ways.
Total number of ways are: $ 3^5 $
Hence, required probability will be $ \frac{10}{27} $.