Answer:
He needs 7 more consecutive successful first serves to raise his first serve percentage to 60%.
Step-by-step explanation:
After n consecutive serves, his total number of serves is going to be n+8, since he has already served 8 times. In the best case, his number of successful first serves is n+2.
His percentage of succesful first serves is the division of the number of succesful first serves divided by the total number of serves. So

We want
. So







He needs 7 more consecutive successful first serves to raise his first serve percentage to 60%.
The answer I got was A.)$56.
Hope this helps!<3
Comment if you need help on how I got that answer!
You need to show me the model, so I can answer the question.
Answer:
24
Step-by-step explanation:
The sum of the their ages is 72. 48 divided by 2 is 24. 48 plus 24 is 72