Question

find the cost of polishing a circular table top of radius 1.4 metre if the rate of polishing is 15 per metre square​

Answer 1

Step-by-step explanation:

total surface area = 3.14×1.4×1.4

=6.15 sq m

total cost = 6.15×15

=92.25

Answer 2

Before, finding the answer. Let's find out on how we can find the answer.

• As they have asked us about polishing, we have to find the Area of Circular Table.

$\boxed{\sf Area \: of \: Circle= \pi r^2}$

π = $\sf \dfrac{22}{7}$

• After finding the Area, we have to multiply it by the rate.

_________________

Given :

• Radius = 1.4 m
• Rate of Polishing = Rs.15

To find :

• Total Rate of polishing

Solution :

Area of Circle = πr²

                       = π × r²

                       $\sf = \dfrac{22}{7} \times 1.4^2$

                       $\sf = \dfrac{22}{7} \times 1.96$

                       $\sf = \dfrac{43.12}{7}$

                       $\sf = 6.16 \: m^2$

Hence, Area of Circular Table is 6.16 m².

Rate for Polishing = Area × Rate

                              = 6.16 × 15

                              = 92.4

Hence, Rate of Polishing is Rs. 92.4.