Question

6. The slant height and base diameter of a conical tomb are 25 m and 14 m respectively.
Find the cost of white-washing its curved surface at the rate of 210 per 100 m.
inker's cap is in the form of a right circular cone of base radius 7 cm and height​

Answer 1

✧ Question :-

Q.6. The slant height and base diameter of a conical tomb are 25 m and 14 m respectively.Find the cost of white-washing its curved surface at the rate of 210 per 100 m.inker's cap is in the form of a right circular cone of base radius 7 cm and height??

✧ Given :-

• Height of the conical tomb = 25m. (slant).
• Base = 14m.
• Rate of whitening = ₹210/100sq.m.

✧ To find :-

• Cost of the white - washing the cone = ??

✧ Solution :-

$\bf {\: given \: slant \: height \: of \: the \: tomb \: = }l = 25m. \\ </p><p> \bf \: radius \: = \frac{14}{2} = 7m. \\ \: </p><p> \bf \: curved \: surface \: area \: of \: the \: tomb \: =\pi \: rl \\ \bf \: = (\frac{22}{ \cancel7} \times \cancel7 \times 25 )m\\ \bf \: = (22 \times 25 )m\\ \bf \: = 550 {m}^{2}$

Now,

$\bf {\: cost \: of \: white - washing \: is \: ₹210 / \: 100m^2. }\\ \bf \: {\therefore }\: cost \: of \: whitening \: 100 {m}^{2} = \frac{1}{1 \cancel0 \cancel0} \times 21 \cancel0 \times 55 \cancel 0 \\ \bf \: = 21 \times 55 \\ \bf \: = ₹1155.\:\:☞\:\: ans.$

Answer 2

₹1155 is the correct answer.