Costs for each person for party

Question

I realise this is very simple but I've thought about it too much that I can't seem to work it out sensibly anymore. Sorry.

Arranging a birthday party for a friend. 17 attendees including the birthday girl.

The activity is 28pp

Dinner deposit 5pp

I paid the birthday girls £5 dinner deposit and the 16 of us split the cost of her activity among us.

28 x 17 = 476 total for activity

5 x 17 = 85 total dinner deposits

561 altogether owed

Instead of 561/16 as I'm covering the food deposit, I just worked out the total each individual owes for themselves, so 28 + 5 = 33

Then the birthday girls activity is split amongst us 16. 28/16 = £1.75 each, which I rounded up to £2 for ease and to cover any decorative bits.

So I asked for £35, is this ok? Ive obviously gone a bit wrong somewhere as the total I've asked for each including me totals 560, just a pound under but I just don't want to be way out and worried ive completely messed it up.

It looks like I'm just ever so slightly under but if anyone is able to confirm it's not completely wrong I'd be grateful! I'm overthought it so much I can't think straight. Thanks!

Answer 1

The 561 total is correct: 17(28+5)

The birthday girl pays nothing.

Each attendee pays for their own activity + dinner deposit (33).

16 of the attendees (including you) split the cost of the activity, so each of the 16 pays an additional 28/16 = 1.75.

There are 15 general attendees who pay 33 + 1.75 = 34.75.

You also pay that amount plus 5 for birthday girl's dinner deposit. So you pay 39.75.

Check:

Birthday girl: 0

General attendee: 34.75 (and there are 15 of them)

You: 39.75.

15(34.75) + 39.75 = 521.25 + 39.75 = 561