I used to love giving people simple puzzles, so here is one for you:
Three people go into a restaurant.
They each eat and the total bill is £30, so they pay £10 each (3 x 10 = 30) and leave.
After leaving, the manager realises he has charged them £5 too much, so sends the waiter after them.
The waiter realises splitting £5 between three is tricky, and besides, he got no tip, so he keeps £2 and gives each person £1 back.
That means each person paid £9.
3 x £9 = £27
Add the waiter’s tip: £27 + £2 = £29
So, where has the other pound gone?
Answer in a couple of days…