Question

The cost of painting the circle is $3 per sq. ft. Calculate the total price of painiting the circle of given diameter 9 ft. (round off to 2 decimal places)
$\text{[Take 𝛑=}\frac{22}{7}]$

• A. $64.64
• B. $127.28
• C. $190.92
• D. $763.71

Answer 1

The correct option is C $190.92

Given :
Diameter(d) = 9 ft
$\text{Radius(r) =}\frac{d}{2}\Rightarrow 4.5ft$

Area of circle = $𝛑r^2$

= $\frac{22}{7}\times 4.5\times 4.5$

= 63.6428 sq. ft

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ∴Area of circle = 63.64 sq. ft

$\text{Rate of painting =}\$3\text{per sq. ft}$

Total cost = Rate x Area
Total cost of painting = $3\times 63.64$
$=\$190.92$