Question

A wooden toy is in the form of a cone surmounted on a hemisphere. the diameter of the base of the cone is 16cm and its height is 15cm. Find the cost of painting the toy at ₹7 per 100cm sq.

Answer 1

d=16
r=16/2=8
s.a of cone =
$\pi r*l$
s. a of hemisphere =
$2\pi \: r {}^{2}$
s. a of toy =
$\pi \: r (l + 2r)$
$l = ( \ \sqrt{h {}^{2} } + {r}^{2})$

l=
$l = \sqrt{15 { } ^ {2} + 8 {}^{2} }$
$l = \sqrt{225 + 64}$
$l = \sqrt{289}$
$l = 17$
s. a of toy =
$22 \div 7 \times 8(17 + 2 \times 8) \\ = 22 \div 7 \times 8(17 + 16)$
$22 \div 7 \times 8 \times 33$
cost =rate *area
cost for painting toy=22/7*8*33*7/100
=5808/100
=58.08 rupees

Answer 2

Answer:

d=16

r=16/2=8

s.a of cone =

\pi r*l  

s. a of hemisphere =

2\pi \: r {}^{2}  

s. a of toy =

\pi \: r (l + 2r)

l =  ( \ \sqrt{h {}^{2} }  +  {r}^{2})  

l=

l =  \sqrt{15 { } ^ {2} + 8 {}^{2}  }  

l =  \sqrt{225 + 64}  

l =  \sqrt{289}  

l = 17

s. a of toy =

22 \div 7 \times 8(17 + 2 \times 8) \\  = 22 \div 7 \times 8(17 + 16)  

22 \div 7 \times 8  \times 33\\  

cost =rate *area

cost for painting toy=22/7*8*33*7/100

=5808/100

=58.08 rupees

Step-by-step explanation: