Both a and b are four-digit numbers and one is obtained from the other by reversing the digits.

Determine them, knowing that 2 * (a + b) = 5 * (b - 1).

Show your reasoning.

FOR a1 = 1 TO 9
 FOR a2 = 0 TO 9
  FOR a3 = 0 TO 9
   FOR a4 = 1 TO 9
    IF 2 * (1001 * (a1 + a4) + 110 * (a2 + a3)) = 5 * (1000 * a4 + 100 * a3 + 10 * a2 + a1 - 1) THEN
     PRINT a1; a2; a3; a4
    END IF
   NEXT
  NEXT
 NEXT
NEXT

 

Posted by Charlie on 2005-09-16 19:38:29