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When a cone and a hemisphere of the same radius are joined along their flat circular faces to make a toy, which expression gives the total outer surface area of the toy?
ACSA of cone $+$ CSA of hemisphere
BTSA of cone $+$ TSA of hemisphere
CCSA of cone $+$ TSA of hemisphere
DTSA of cone $+$ CSA of hemisphere
Answer & Solution
Correct answer: A. CSA of cone $+$ CSA of hemisphere
The common circular faces are internal after joining, so they are not exposed. Therefore only the curved outer parts are counted: the curved surface area of the cone and the curved surface area of the hemisphere.
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