The manager of a nightclub has observed that the number of male customers who visit the club follows a Poisson distribution with a mean of 30 per day, and the number of female customers who visit the club follows a Poisson distribution with a mean of 20 per day. The entrance ticket is $20 per male and $10 per female. (10 marks) a. Find the probability that 10 males will visit the club on a randomly selected day. b. If the number of males and female visitors are mutually independent, find the mean and the standard deviation of the club earnings through entrance ticket earnings. Please answer in detail.. Thank You!