I think the answer is a = 4.5
81 ÷ 6 ÷ 3 = 4.5
I hope this helps, have a wonderful day!
Answer: 60 miles
Step-by-step explanation:
Given
It takes ferry 2 hours to travel to town A and only
to travel back to town B.
Speed of current is 
Suppose the speed of the ferry is
mph
Distance traveled in both the cases is same, but it took more time traveling to city A that is, ferry is moving upstream and downstream for returning time.

Distance between the towns is 
Answer: I believe its 5/9
Step-by-step explanation:
As you can see, the only fraction that doesn't equal 0.53, or the outlier, is 5/9 or 0.5556
Answer:
2^21
Step-by-step explanation:
3+18=21