your formula gives the total cost of the party. If you wants to calculate amount each person had to pay you divide it by p-5
If a party cost £100 to hire a venue, and £10 per person for refreshments, five guests don't pay anything, but all other people will be asked to pay equal amounts, how do I know if the formula I create is in the right order?
I thought;
n = £100 + £10p
This gives me two unknowns and I am not sure how to work it out?
Any help much appreciated
The cost per person is the cost of the party [x(n)] divided by the number of people attending (n).
The cost of the party you (correctly) have as x(n) = £100-10n
The amount of people who pay are the n people who attend minus the 5 who do not pay (assuming they all attend)
where y(n) is the cost per person.
The value of x(n) or y(n) cannot be determined without a value of n.