It takes Annie an average of 60 sec. to solve a Rubik's cube. You come in with a Rubik's cube and mix it all up and ask her to solve it. Let R be the amount of time it takes Annie to solve the Rubik's cube.
1. In a contest of 5 min. there are several mixed up Rubik's cubes to be solved. Let K be the number of Rubik's cubes that Annie can solve in 5 minutes. She solves each cube independently of the others. What is the distribution and parameters of K?
2. What is the probability that Annie solves at least 4 Rubik's cubes in the 5 min. contest?
3. If annie solves the Rubik's cube 6 times in the 5 min contest, what is the probability that she solved 2 of them in the first 90 sec of the contest?