[quote="j_shreyans"]Each of the positive integers a, b, and c is a three-digit integer. If each of the digits 1 through 9 appears in one of these three integers, what is the minimum possible value of the sum of a, b, and c?
A)45
B)666
C)774
D)801
E)1368
OA[spoiler]C[/spoiler][/quote]
The key point is that the sum of the 3 integers must be as minimum as possible.
Let a = rst
Let b = uvw
Let c = xyz
So the Hundred's digit (i.e., digit 'r' in the number rst) should be as small as possible.
For this let the r = 1, u = 2, x = 3
Next the Tens's digit (i.e., digit 's' in the number rst) should be as small as possible.
For this let the s = 4, v = 5, y = 6
Next the Unit's digit (i.e., digit 't' in the number rst) should be as small as possible.
For this let the t = 7, w = 8, z = 9
So we have the three numbers as a = 147, b = 258, c = 369
The sum would then come out to be [spoiler]774[/spoiler] which is the least possible
