posted by GWPeAYsBnmh .
Young Saul, a budding mctaemhtiaian and printer, is making himself a fake ID. He needs it to say heâ€™s 21. The problem is heâ€™s not using a computer, but rather he has some symbols heâ€™s bought from the store, and thatâ€™s it. He has one 1, one 5, one 6, one 7, and an unlimited supply of + â€“ * / (the operations addition, subtraction, multiplication and division). Using each number exactly once (but you can use any number of +, any number of -, â€¦) how can he get 21 from 1, 5, 6, 7?Note: you canâ€™t do things like 15+6 = 21. You have to use the four operations as â€˜binaryâ€™ operations: ((1+5)*6)+7.
No hablo mctaemhtiaian