Replace the letters in the diagram with a different number from 0 to 9, such that the sum of the four numbers on all edges are the same, and the sum of the three numbers on all three corners are the same.

A
B C
D E F
G H I J

*In other words, A+C+F+J = A+B+D+G = G+H+I+J and*

A+B+C = D+G+H = F+I+J.

(In reply to

answer by K Sengupta)

Nope. You have duplicated the digit 6 ...