In the figure, what is the value of a?
A
30
B
45
C
72
D
60
Correct Answer: 72
a0 = 2b0 b0 = 3c0 2b0 = 6c0 6c0 + 3c0 + 2b0 = 1800 2b0 + b0 + 2b0 = 1800 b0 = 1800/5 b0 = 360 a0 = ( 2×36)0 = 720