| Giver | Post | Date |
| Anderson Phiri | Re: If pqr s is a four-digit number, where p, q, r and s are the digits, | 28-Jun-2019 |
| GoodnessShallPrevail | Re: If pqr s is a four-digit number, where p, q, r and s are the digits, | 05-Sep-2017 |
| pclawong | Re: If pqr s is a four-digit number, where p, q, r and s are the digits, | 17-Aug-2017 |