Poisson process question: Two type of customers can come to a store, males or females,

males arrive at a rate of 10 per hour, while female arrive at a rate of 5 per hour,

1. What is the expected number of males, if it is known that during 3:00pm to 4:00pm, we have 12 customer.

2. compute the probability that exactly 2customers (male or female) entered during a 20mins window (let say 4:00pm to 4:20pm)