Question 805551
 it is an odd number with three digits.
a, b, c
:
 All the digit are different and add up to 12.
a + b + c = 12 
:
He difference between the first two digits equals the difference between the last two digits.
a - b = b - c
a = 2b - c
2b = a + c
:
We can replace a + b in the 1st equation with 2b
2b + b = 12
3b = 12
b = 4
therefore
2(4) = a + c
a + c = 8
:
 What is the number? 741, only odd number that works