Question

The cost of levelling a circular field at Rs 3.5 per square meter is Rs.1100. The cost of putting up a fence all round it at Rs.3.50 per meter is

• A. 228
• B. 358
• C. 248
• D. 220

Answer 1

Answer:

D. 220

$Amount=Area\times{Rate}$

$Area=\pi{r^2}$

$Rate = 1 Rs$

$\pi{r^2}\times{3.5}=1100$

$\frac{22}{7}\times{r^2}\times{\frac{7}{2}}=1100$

$11\times{r^2}=1100$

$r^2=100$

$r=10$

Cost of Fencing,

$Perimeter \times{rate}=Amount$

$2\pi{r}\times{Rate}=Amount$

$2\pi{r}\times{3.50}=Amount$

$2\times{\frac{22}{7}}\times{10}\times{3.50}=Amount$

$Amount=10\times{22}$

$Amount = 220$

Cost pf putting up fencing around id Rs.220.