Draw a tree to represent this tennis match and answer the following questions . ( a ) What is the expected value for the number of sets that will be

Can someone help me answer this?? I am confused...

Draw a tree to represent this tennis match and answer the following questions .( a ) What is the expected value for the number of sets that will be played ? ( Hint : We only care about the number of sets played , not who wins . )( b ) What is the expected value for the number of sets that Kim will win ? ( Hint : We only care about the number of sets Kim wins during the match , not if she ended up winning the match in the end . )