Answer :
So,
Mark wants $100 for 10 hrs., or $10/hr.
Rick wants $80 for 9 hrs., or [tex] \frac{80}{9} /hr. or [/tex] $8.89/hr.
Steve wants $75 for 8 hrs., or $ [tex] \frac{75}{8} [/tex] /hr. or $9.38/hr.
Finally, Andy wants $60 for 5 hrs., or $12/hr.
We can see that Rick offers the best deal, at $8.89/hr.
Mark wants $100 for 10 hrs., or $10/hr.
Rick wants $80 for 9 hrs., or [tex] \frac{80}{9} /hr. or [/tex] $8.89/hr.
Steve wants $75 for 8 hrs., or $ [tex] \frac{75}{8} [/tex] /hr. or $9.38/hr.
Finally, Andy wants $60 for 5 hrs., or $12/hr.
We can see that Rick offers the best deal, at $8.89/hr.
Mark charges $10.hour. Rick charges $8.89.hour. Steve charges $9.38/hour. Andy charges $12/hour. The best deal is to take tennis lessons from Rick.
So Rick would be the choice