Explanation:

The area of rectangular plot= 330 m^2

Breadth=15 m

Let x be the length of the rectangular plot and y be the breadth.

Area=330

xy= 330

15x=330    (because y=15)

x=22

So, Length= 22 m

We want to find the cost of fencing, so first find perimeter of the rectangular plot as follow:

Perimeter= 2(x+y)= 2( 22+15)=2*37=74 m

Now, The cost of fencing per meter= Rs 8.50

So, The cost of 74 m of fencing= 8.50*74= 629

Hence, option 3 is the correct answer.