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Question
A frustum of a right circular cone is of height 16 cm with radius of its ends as 8 cm and 20 cm. Then, the volume of the frustum is
Options
3328π cm3
3228π cm3
3240π cm3
3340π cm3
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Solution
3328π cm3
Explanation;
Hint:
Here, h = 16 cm, r = 8 cm, R = 20 cm
Volume of the frustum
= `1/3pi"h"("R"^2 + "r"^2 + "Rr")`
= `1/3pi xx 16(20^2 + 8^2 + 20 xx 8)`
= `1/3 pi xx 16(400 + 64 + 160)`
= `1/3 pi xx 16 xx 624`
= π × 16 × 208
= 3328π cm3
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