Lines L1 and L2 are parallel to each other. what is the value of x ?
A
60°
B
120°
C
90°
D
30°
Correct Answer: 60°
Choosing ways where all 5 are of one kind and subtracting from all ways... total ways - 10C5 all one of a kind - 6C5 total selections = 10!/5!5!−6!/5!1! = 246