Find the lowest integral (integer) values for A, B, C, and D where: A + B = C , A + D = B, 2C = 3D, B > 0?

Question

A + B = C
A + D = B
2C = 3D
B > 0

Answer 1

A = 1
B = 5
C = 6
D = 4

A + B = 1 + 5 = 6 = C
A + D = 1 + 4 = 5 = B
2C = 2*6 = 12 = 3*4 = 3D
B = 5 > 0

Answer 2

what should be lowest ?
should the sum of all numbers be as small as possible ?, the mean of all numbers be as small as possible ? do you want just any number to be as small as possible, ..

2C = 3D =>c=d=0 lead to nothing because constraint b > 0

smallest integral (and positive) c and d are c=3 and d=2 etc. but that goes wrong also since 2a + d = c, so next is c=6 d = 4 and that is what previous poster found.