Can you solve these mental workouts? Some need lateral thinking - solving problems by an indirect and creative approach, typically through viewing the problem in a new and unusual light.
Three friends shared a meal at a restaurant. They split the bill after the meal. The bill is £30, so each guest pays £10.
Then the waiter realises he's made a mistake and the bill should be £25. So he takes £5 from the till to return to give it back.
But on his way back to the table, he realises that he cannot divide the money equally. So he decides to just give each of the friends £1 and keep £2 for himself.
So each guest got £1 back and they have paid £9, bringing the total paid to £27.
The waiter has £2. £27 + £2 = £29 so, if the friends originally gave £30, what happened to the remaining £1?