# The total surface area of a hollow cylinder which is open from both sides is 4620sq. cm, area of base ring is 115.5sq. cm and height 7 cm. Find the thickness of the cylinder.(with explanation please)

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by Arpn

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by Arpn

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curved surface area + 2(area of base rings) = 2h(R+r) + 2(R2 -r2).....................1 also, = 2(R +r)(h + R -r)...........................2

total surface area of hollow cylinder = 4620 sq cm

so,

2h(R+r) + 2(R2 -r2) = 4620

area of base rings = 115.5 sq cm

so,

2h(R+r) = 4620 - 2(115.5)

2(R+r) = 4389/7 {here h = 7cm} =627....................3

now from eq 2

2(R +r)(h + R -r) = 4620

(h + R -r)=4620/627 {from eq 3}

R -r = 7.36842 - 7

R -r = .36842 cm

so thickness of given cylinder = .36842 cm