Three men eat at a restaurant. The bill comes to £25. They each pay £10. When the waiter brings the £5 change
they each take back £1 each and leave a £2 tip. So each man has paid £9, which totals £27. The waiter has the £2 tip, which makes £29, so where's the other £1 gone?

It never existed. The £3 comes from a different place so should never be included in the main sum. Simply the men take £1 back each and the waiter gets £2. That makes £30 with the £25 bill.

I think the real mystery here is how did they manage to get a bill between 3 of them to equal exactly £25?

1 fillet steak £24
1 bottle of water each for the other 2 at 50p each

Correct. Big tick and a gold star

Since I was first in there I'll set another:

Using the number 8 exactly 8 times (and no other numbers, including 0) Can you show the sum to make exactly 1000?

888
+88 = 976

8+8+8=24

976+24 = 1000

(or 2850 in Querty's calculator)

8888/8.888?