Question

A solid iron cylinder has Total surface area of 1848 Sq.m. it's csa is five sixth of its total surface area find its radius and height of the iron cylinder where radius×height=245

Answer 1

TSA=1848 m^2

CSA=(5/6) the of TSA

TSA of a cylinder =2πr(h+r)

1848=2 x 22/7 x r x (h+r)

1848 ÷22/7÷2= r x(h+r)

294=r x (h+r) ------1

CSA = 5/6 ×1848

=1540

CSA of a cylinder = 2πrh

1540= 2×22/7×r×h

1540÷2÷22/7=r×h

245=r×h

245/r=h

Sub 245/r= h in 1

294=r(245/r +r)

294=245+2r

294-245=2r

49=2r

r=24.5

h=245/r

=245/24.5

=10

Radius =24.5 m

Height=10m