Question

The sides of a rectangular field are in the ratio 3:4. If the area of the field is 7500 sq.m, the cost of fencing the field at 25 paise per metre is:

• A. Rs.55.50
• B. Rs.67.50
• C. Rs.86.50
• D. Rs.87.50
• E. Rs.89

Answer 1

The correct option is D

Rs.87.50

Let length = (3x) metres and breadth = (4x) metres Then, 3x $\times$ 4x = 7500 $\iff$12x${}^2$ = 7500 $\iff$ x${}^2$ = 625 $\iff$ x = 25 So, length = 75 m and breadth = 100 m Perimeter = [2 (75 + 100)] m = 350 m. $\therefore$ Cost of fencing = Rs. (0.25 $\times$ 350) = Rs. 87.50