Question

if the radius and the height of the cylinder are in the ratio 5 : 7 and its volume is 550 cm cube then find its radius............

correct answer is required only

Answer 1

Radius divided height 5/7 cross multiply it and take h one side volume of cyclinder is pie r2 h
See it above

Answer 2

Step-by-step explanation:

Let the radius of the cylinder = 5x and the height of the cylinder = 7x

The volume of the cylinder =pi*(r^2)h =(22/7)(5x)^2*7x = 550 cc. or

x^3 = 550*7/(22*25*7) =1, or

x =1)^(1/3) = 1

therefore, length = 5x = 5×1= 5 cm

height = 7x = 7×1 = 7 cm

c.s.a of cylinder = 2 π r h

= 2 × 22/7 × 5 × 7

= 220 cm²

t.s.a of cylinder = 2πr(r+h)

= 2 ×22/7× 5(5 +7)

= 377.14 cm²

ratio of c.s.a to t.s.a = 220 :377.14

= 7 :12