I need help with a business and finance assignment

Answer the two questions
Callie’s Canine Cottage has 45 kennels for boarding dogs. During June, July, August, November and December, each of the kennels is booked. During these months, Callie’s always charges its regular price of $15 per day per kennel. When business is slow, Callie’s sometimes charges a discounted rate of $13 per day per kennel for the first 25 kennels booked and $15 for the rest. On September 15^th, Callie’s filled 25 kennels at $13 per day and 10 kennels at $15 per day. Calculate Callie’s yield for September 15^th.*
What are the challenges and risks in using yield management