9514 1404 393
Answer:
91, including Mr. Jones
Step-by-step explanation:
The total cost for n people to go on the trip will be ...
C(n) = 45n +1295
If Mr. Jones does not pay anything, this cost is divided among the remaining (n-1) persons, so the cost per person is ...
[tex]c(n)=\dfrac{C(n)}{n-1}\\\\c(n)=\dfrac{45(n-1)+45+1295}{n-1}=45+\dfrac{1340}{n-1}[/tex]
We want to find n such that c(n) < 60.
[tex]45+\dfrac{1340}{n-1}<60\\\\\dfrac{1340}{n-1}<15\qquad\text{subtract 45}\\\\\dfrac{1340}{15}<n-1\qquad\text{multiply by $\dfrac{n-1}{15}$}\\\\90\dfrac{1}{3}<n\qquad\text{add 1}[/tex]
A total of 91 people would need to attend in order for the cost per person to be less than $60.