Q5 of 32 Page 250

A self-help group wants to manufacture joker’s caps of 3 cm. radius and 4 cm height. If the available paper sheet is then how many caps can be manufactured from that paper sheet?


Given that, the radius(r) of cone is 3 cm and height (h) is


4 cm.


And, the available paper sheet is- 1000 cm2


And, Surface area of cone is - πrl


Also, slant height(l) = √ r2 + h2


⇒ l = √ 32 + 42


⇒ l = √ 9 + 16


⇒ l = √ 25


⇒ l = 5


⇒ Surface area of joker’s cap



And, the available paper sheet is- 1000 cm2


⇒ No. of caps that can be manufactured from that paper sheet




= 21.21 cm2


= 21 cm2


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