In the figure above, the value of b is?
A. 20
B. 40
C. 42
D. 80
E. 100
The OA is B.
This PS question can be solved in the following way,
(5a) + (4a) = 180, then a = 20.
And (4a) = (b + 40) (vertically opposite), also we can say (b + 40) + (5a) = 180.
Finally, b = 40.
Is there a strategic approach to this question? Can any experts help? Thanks!
