Question

A manufacturing involves ten children in colouring playing tops lattus each of which is shaped like a cone surmounted by a hemisphere. The entire top is 5cm in height and the diameter of the top is 3.5cm. Find the area they have to paint if 50 playing tops were given to them for painting. Please explain every step of the solution.

Answer 1

Here,
Given:diameter d =3.5cm,Total height of top (th)=5cm
For hemisphere,
radius r=height h=d/2=3.5/2=1.75cm
For Cone,
height h=th-r=5-1.75=3.25cm
slant height l= √((h^2)+(r^2))=√((10.5625)-(3.0625))=√7.5=5√3=8.66cm
T.S.A of 50 top= 50(C.S.A of cone + C.S.A of hemisphere)
=50(πrl+2π(r^2))
=50(πr(l+2r))
=50×(22/7)×1.75×(8.66+3(1.75))
=50×(22/7)×1.75×(8.66+3.5)
=50×(22/7)×1.75×(12.16)
=3344 cm^2

Answer 2

Answer:  The answer is 1980 cm2

Look at the attachment below.