lng rordoin a party contextat the Vine House HotelYour House Hotelparty $20 $750 Chargesfor Sarah per 30 ow thperson pluspeoplethat there for the will be each personcost will 60 extra be people at the party.

So in this problem we can see that there will be 60 people at the party. Following the conditions for this event that state the following: $750 for up to 30 people and every extra person pays $20. To show that the cost will be $1350 in total we simply do this:
For 30 people we have $750 dollars. Now every other person after pays only $20. That means that another the other 30 people will pay in total only $600.
If we add them we get: $750 + $600 = 1350. This shows that the cost will be $1350.
I
hope it helps, Regards.