Question 6 - A-Level Maths

6. (a) Draw the activity network described in this precedence table, using activity on arc and dummies only where necessary.

Activity	Immediately preceding activities
A	-
B	-
C	-
D	B, C
E	A
F	C
G	D, E
H	D, E
I	\(F , G\)
J	C
K	\(G , H\)

(b) Explain the possible reasons dummies may be needed in activity networks.