Question

Andy spent ₹ 450 in fencing the parallelogram shaped land (leaving 1 m for the gate).. If Andy starts from a point 5 m away from A (on side AB) and take the shortest possible path to the opposite side, he would reach D. Andy restructured his land to be a rectangle having the same base and same height. Find the cost of fencing the new land in at ₹ 6 / m.

• A. ₹. 432.47
• B. ₹. 444
• C. ₹ 431.47
• D. ₹. 438

Answer 1

The correct option is D

₹. 438

Let us redraw the figure given like this. With what is given in the question, we can say that DE is the height of the parallelogram.

Let the unknown side of the parallelogram be ‘$x$’ m.

Perimeter of the parallelogram field which is fenced $=\frac{450}{6}=75m$

So, $(2\times 25+2x-1)=75$

$2x–1=25$

$x=13m$

In $\Delta ADE,AD=13m,AE=5m$

Using Pythagoras theorem,

$A{D}^2=A{E}^2+D{E}^2$

or, $D{E}^2={13}^2-5^2=144={12}^2$

So, $DE=12m$

The restructured land is in the shape of a rectangle with same base and width.

So, length of the rectangular land $=25m$

Breadth of the rectangular land $=12m$

Perimeter $=2(l+b)=2(25+12)=2\times 37m=74m$

Perimeter to be fenced $=(74-1)m=73m$

Cost of fencing $=(₹.6/m)\times 73m=₹.438$