Question
If a + b = 12 ,
b + c = 17
and c + a = 11 what is the value of a + b + c?
A. 10
B. 12
C. 20
D. 18
Answer: C. 20
Solution:
a + b = 12 …(A)
b + c = 17 …(B)
c + a = 11 …(C)
Adding (A), (B) and (C) we get,
2(a + b + c) = 40
Dividing both sides by 2 we get,
a + b + c = 20
