The length of diameter of base of a hemispherical tomb is 42 dcm. Calculate the cost of colouring the upper surface of the tomb at the rate of ₹ 35 per square metre.

Explanation

The diameter of base of the hemispherical tomb = 42 dcm
`therefore ` its radius ` =42/2 ` dcm =21 dcm
` therefore ` the surface area of the upper surface of the tomb
` =2 xx 22/7 xx 21^2` sq. dcm = 2772 sq. dcm= 27. 72 sq. metres
So the cost of coluring the tomb `= ₹ 27.72 xx 35 = ₹ 970.2 `
Hence the required cost = ₹ 970.2