Question

The cost of levelling a square lawn at Rs 15 per square metre is Rs 19935.Find the cost of fencing the lawn at Rs 22 per metre. The answer is ₹3256 in my book.

Answer 1

Answer:

• Total cost of fencing the square lawn = ₹ 3207.6.

Given :

• Total cost of leveling the square lawn at Rs. 15 per square meter = ₹ 19935

• Cost of fencing the square lawn = Rs. 22 per meter.

To find :

• Total cost of fencing the square lawn =?

Step-by-step explanation:

Total cost of leveling the square lawn at Rs. 15 per square meter = ₹ 19935 [Given]

Area of the lawn = Total cost/Cost per square meter

Substituting the values, we get,

= 19935/15

= 1329 m²

So, Area of the square lawn = 1329 m²

We know that,

 

Area of the square = Side²

Substituting the values in the above formula, we get,

= √1329

= 36.45 m.

So, each side of the square lawn = 36.45 m

Now, 

Perimeter of square = Perimeter of the square lawn = 4 × Side

Substituting the values in the above formula, we get,

= 4 × 36.45

= 145.8 m

Hence, Perimeter of the square lawn = 145.8 m

Now,

Cost of fencing the square lawn = Rs. 22 per meter [Given]

Total cost of fencing the square lawn = Perimeter of the square lawn × cost of fencing of the square lawn.

Substituting the values, we get,

= 145.8 × 22

= 3207.6

Thus, Total cost of fencing the square lawn = ₹ 3207.6.

Answer 2

Given :

The cost of levelling a square lawn at Rs 15 per square metre is Rs 19935.Find the cost of fencing the lawn at Rs 22 per metre.

To find :

Find the cost of fencing the lawn at Rs 22 per metre

Solution :

Area of the square lawn = $\sf \frac{Total\:cost}{Rate}$

= $\sf \frac{19935}{15}=1329m^2$

Area of square lawn = 1329m²

=> side × side = 1329

=> (side)² = 1329

=> side = √1329 = 36.45m

Now,

Perimeter of square lawn

= 4 × side

= 4 × 36.45

= 145.8m

The cost of fencing the square lawn at rs 22 per metre

= 145.8 × 22

= Rs.3207.6

${\boxed{\red{\sf{Cost\:of\:fencing\:the\:lawn=Rs.3207.6}}}}$

Note :

• Area of rectangle = length×breadth
• Perimeter of rectangle = 2(l+b)
• Area of square = side×side
• Perimeter of square = 4×side