Disrete Probability and Poisson distribution

1. You roll 7 dice at once. Find the probability that 2 of them will roll more than 2.
Answer: 3.84%

2. On average, 2 major earthquakes with a magnitude of 8 or more occur each year. Calculate the probability of 11 major earthquakes happening during 3 years.
Answer: 2.25%

Please, help to understand the answer and how to solve these tasks.