Let the numbers be a, b and c in order of size. b is 14 as it is in the middle c - a = 12 so c = a + 12 (a + b + c)/3 = 10 a + b + c = 30 a + 14 + (a + 12) = 30 2a + 26 = 30 2a = 30 - 26 = 4 a = 2 c = 2 + 12 = 14 So the three numbers are 2, 14 and 14
