During normal working hours, the help desk of a car repair company(also repairs small amount of motorbikes) receives telephone calls according to a Poisson process at the rate of 25 calls per hour.

it has been noted that 5% of calls relate to the company’s motorbike repairs.

Calculate the probability that exactly four calls are received between 10.20am and 10.30 am, exactly one of which relates to motorbike repairs.

Exactly eight calls are received between 10.20am and 10.30am one morning. Calculate the probability that exactly two of them relate to motorbike repairscan any one show me how this is done please , thanks.