If a + b + c = 83 and a + b + c = 15, then the value of (ab + bc + ca) is :

If a + b + c = 83 and a + b + c = 15, then the value of (ab + bc + c

1.	If a + b + c = 83 and a + b + c = 15, then the value of (ab + bc + ca) is :
A.	69
B.	70
C.	71
D.	72
Answer» D. 72