Two friends had a meal that cost $25 total and each paid $15, but the cashier returned $5 in change to the waiter. The waiter kept $3 as a tip and returned $1 to each friend. While the friends paid $14 each, totaling $28, and the waiter received $3, this accounts for $31 of the original $25 bill, with $1 unaccounted for.

2. Two friends have a meal together, and the bill is $25.
They pay $15 each, which the waiter gives to the cashier.
The cashier hands back $5 to the Waiter.
The waiter keeps $3 as a tip and hands back $1 each.
So, the friends paid $14 each for the meal, for a total of
$28. The waiter has $3, and that makes $31.
Where did the other dollar come from?