Question

The diameter of a semicircular table is 10 cm. Find the cost of polishing the semicircular table top at ₹ 3.50 per sq.cm. *​

Answer 1

$\huge{\bold\color{blue}{answer}}$

$\large{\bold{\underline{ \: Rs \:137.50 }}}$

$\huge{\underline{\underline{\underline\color{red} \: \: \: \: \: ✿Required Answer:-✿ \: \: \: \: }}}$

We have,

• Diameter = 10 cm
• Cost of polishing = Rs. 3.50/cm²

➠ And we have to find the cost of polishing the semicircular table top which will be half the area of a full circle of Diameter 10 cm.

$Radius = \frac{10}{2} = 5 cm$

Finding the area of semicircular top:

$= \frac{πr ²}{2}$

$= \frac{22}{7} × \frac{5²}{2}$

$= \frac{11}{7}× 25$

= 39.28 cm² (approx.)

✿ Finding total cost of polishing:

= Cost of 1 cm² × Area

= Rs. 3.50 × 39.28

❤️= Rs. 137.48 \approx≈ Rs. 137.50

Hence:-

The total cost of polishing the semicircular top is:

$\huge{ \boxed{ \sf{ \red{Rs. \: 137.50}}}}$

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Answer 2

Answer:

Required Answer:-

We have,

Diameter = 10 cm

Cost of polishing = Rs. 3.50/cm²

And we have to find the cost of polishing the semicircular table top which will be half the area of a full circle of Diameter 10 cm.

Radius = 10 cm / 2 = 5 cm

Finding the area of semicircular top:

= πr² / 2

= 22/7 × 5²/2

= 11/7 × 25

= 39.28 cm² (approx.)

Finding total cost of polishing:

= Cost of 1 cm² × Area

= Rs. 3.50 × 39.28

= Rs. 137.48 \approx≈ Rs. 137.50

Hence:-

The total cost of polishing the semicircular top is:

₹137.50