Answer:
B
Step-by-step explanation:
Let say, a=9,b=11,c=6
Then associative properties says that every element is related to each other, here "b" associates a &c.
Therefore, a is related to b+c
c is related to a+b
70 or 60 is the answer
144 classes. each class is 10 minutes. 6X24= 144
