Let the middle digit be x. Then, 2x = 10 or x = 5.So, the number is either 253 or 352. Since the number increases on reversing the digits, so the hundred's digit is smaller than the unit's digit. Hence, required number = 253.
Average of 8 consecutive odd numbers = 656/8 = 82∴ Fourth number = 82 - 1 = 81∴ First numbers = 75Average of 4 even numbers = 87∴ Second even number = 87 - 1 = 86Second largest even number = 88∴ Required sum = 75 + 88 = 163