Answer:

Step-by-step explanation:
The tunnel, the ground and the depth of the tunnel form a right angle triangle.
The length of the tunnel is the hypotenuse of the right triangle that has been formed.
Let the length of the tunnel be
.
Using the sine ratio, we obtain;

The length of the opposite side is 
We substitute the given values to obtain;


We cross multiply to obtain;


Therefore the correct answer is C.
(1/4ab)^-2
Remove negative exponent by rewritten the equation as (4ab)^2
AUse Product rule to get:
4^2a^2b^2
Now raise 4 to the second power to get:
16a^2b^2
The last answer is correct.
It is convenient to let a spreadsheet or graphing calculator do the math for this. Functions can be defined for cost and profit, and evaluated at each of the volumes of interest.
a1) For 200 cars, the Outside location yields the greatest profit
a2) For 300 cars, the City location yields the greatest profit
b) The sites yield the same profit for a volume of 278 cars.