# A PEN STAND IS CYLINDRICAL IN SHAPE WITH BASE RADIUS 3.5 CM AND HEIGHT 10.5 CM .HOW MUCH CARDBOARD WILL BE REQUIRED TO MAKE 25 SUCH PEN STANDS/ ALSO FIND VOLUME OF 1 PEN STAND

2
by raveenaraj

2015-03-26T14:21:03+05:30
height of cylinder=10.5 cm
Total surface area of cylinder=2πr(r+h)
2x22/7x3.5(3.5+10.5)⇒22x14=308cm²
for 1 cylinderstand cardbord sheet require=308cm²
for 25.....................................................=308x25=7700cm²

volume of cylinder=πr²h=22/7x3.5x3.5x10.5=404.25cm³
in a website
https://www.easycalculation.com/area/cylinder.php
maine calculator use kiya hai
your method of solving question is right,but there is error in answer
wat
2015-03-26T14:21:27+05:30
WKT:
BASE (b)=3.5cm
HEIGHT(h)=10.5cm
here we need to find TSA of that cylinder and *25
so TSA=2πr(r+h)
by this we do
⇒2 × 22/7 × 3.5 (3.5+10.5)
⇒ 308m² is the amount of cradboard needed for 1 stand
then for 25 stands⇒its 25*308 ⇒ 7700m²

volume = πr²h
⇒22/7 * (3.5)² * 10.5≈ 403.883

if there are  any mistakes in answer pls inform me i ll check