Hi fellow math geeks

Here I have these problems for you to solve:


1. Lets assume that the number of cars driving by a farm is poisson-distributed and that on average 12 cars pass by the farm every hour (mean 12 cars per hour). John the farmer wakes up and begins to monitor the traffic at 9:00. At 9:10 two cars have passed by. What are the odds that John will see the next car pass by between 9:20-9:30?


2. A Company buys similar parts from two suppliers. 70% of the parts come from one supplier and 10% of his parts are faulty. The rest of the parts comes from the other supplier and 20% of his parts are faulty. Now the Company gets a delivery but doesn't know from which supplier it came from. 20 parts are taken from this delivery and examined and one of them is faulty. What are the odds that this delivery comes from the supplier that sells the inferior product (that is who has higher percentage of faulty parts)?