Question

A3. A rectangular park of dimensions 40 m x 30 m and
a square park of side 120 m have to be developed at
the cost of ₹ 560/m2. Find the total cost involved in
developing the parks.​

Answer 1

Step-by-step explanation:

A rectangular ground is 40 m long and 30 m wide. A 3 m wide path, parallel to its length and width, is in the middle of the ground. What is the area of the path?

5.50% simple interest p.a.

Well, the circumference of the area of the lot is 40 + 40 + 30 + 30 = 140 meters. Since the the path is 3 meters wide, it would appear that the area is 140 x 3 = 420 square meters. However, since this is an inside rectangle, we duplicate a 3 x 3 meter area at each of its 4 corners and we need to deduct 3 x3 x4 = 36 for a final answer of 384 sq. meters.

As an alternative resolution and cross-check we could also say that say that we pave each side of the lot with a 40 x 3 = 120 x 2 = 240 sq.meters. But we need to add the two short sides which are now only 24 meters long, namely the 30m lot width minus the two 3m strips on each side which are already paved. So we add 2 x 24 x 3 = 144 sq.m. and our final result is 240 + 144 = 384 sq. meters. Perfect match, so the answer is proved correct.

Answer 2

Answer:

Step-by-step explanation: