Question

A circular photo frame has an outer radius 20cm and inner radius 18cm find the width of the frame around the photo also find the cost of painting it with a metallic colour at the rate o.7 per cm

Answer 1

the first answer, and cost u can find out multiplying0. 7 to this no.

Answer 2

The width of the frame around the photo is 2 cm and the cost of painting it with a metallic colour is Rs.167.1999

Step-by-step explanation:

Outer radius of circular plate R = 20 cm

Inner radius of circular plate r = 18 cm

Width = Outer radius - Inner radius = 20-18 = 2 cm

Area of frame = Outer area - inner area

Area of frame =$\pi R^2 - \pi r^2$

Area of frame =$\frac{22}{7}(20^2-18^2)=238.857 cm^2$

Cost of painting 1 sq.cm. = rs.0.7

Cost of painting 238.857  sq.cm. =$0.7 \times 238.857 = Rs.167.1999$

Hence the width of the frame around the photo is 2 cm and the cost of painting it with a metallic colour is Rs.167.1999

#Learn more:

A mirror of length 20cm and width 15cm is to be framed with a 2 cm wide frame . find the area of the frame required . Also find the cost of framing at the rate of 15 per cm2​

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