Find the cost of fencing a field in the shape of a rectangle of length $ 25\;{\text{m}} $ , and breadth $ 15{\text{ m}} $ , if the cost fencing is Rs $ 10 $ per meter.

Hint: Here we are given dimensions of the rectangle shaped field to which fencing is to be done, so first of all we will find the perimeter and then the cost accordingly and then will simplify for the resultant required answer.

Complete step by step solution:
First of all draw the diagram with the given dimensions.

Now, the perimeter of the rectangular shaped field is equal to the sum of all the four sides of the field.
Therefore perimeter $ P = 25 + 15 + 25 + 15 $
Simplify the above equation finding the sum of the terms on the right hand side of the equation.
 $ P = 80m $
We are also given the cost of the fencing.
 $
  1{\text{ m = 10 Rs}}{\text{.}} \\
  \therefore {\text{80}}\,{\text{m = 10}} \times 80 = 800\,{\text{ }}Rs. \;
  $
Hence, the cost of fencing the rectangular shaped field is Rupees $ 800 $
So, the correct answer is “800 Rs.”.

Note: Do not forget to put the unit after the perimeter and the area value. Always remember the difference between the area and perimeter. Area is the inside space or the region whereas the perimeter is the outer edge or the surface. Area is measured in square units whereas perimeter in units such as meter, centimetre.