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.
Let a = 1000w + 100x + 10y + z
2002 (w+z) + 220(x+y) = 5000w + 500x + 50y +5z - 5
Now, left hand side is even hence right hand side even. This imples that z is odd. Also, right hand side divisible by 5 implies that (w+z) = 5 OR 10 OR 15. Used brute force with smaller possibilities and got 6359
Posted by Andre
on 2005-09-16 19:13:05