Question 177
The rule of an "obstacle course" specifies that at the $n$th obstacle a person has to toss a die $n$ times. If the sum of points in these $n$ tosses is bigger than $2^n$, the person is said to have crossed the obstacle.
(1) At most how many obstacles can a person cross?
(2) What is the probability that a person crosses the first three obstacles?
(1) At most how many obstacles can a person cross?
(2) What is the probability that a person crosses the first three obstacles?