Let the numbers be x, x + 2, x + 4, x + 6, and x + 8Avg = x + x + 2 + x + 4 + x + 6 + x + 8/5 = 40Therefore, 5x + 20 = 200Therefore, x = 180/5 = 36Therefore, r = x + 4 = 40 s = x + 6 = 42Therefore, Product = 1680
Let the ten's digit be x and unit's digit be y. Then, number 10x + y.Number obtained by interchanging the digits = 10y + x.(10x + y) + (10y + x) = 11(x + y)which is divisible by 11.