Question

The curved surface area of cylinder is 154 cm square the total surface area is three times its curved surface area find the volume

Answer 1

T.S.A = 3*154 = 462 cm²

C.S.A = 154 cm²

C.S.A = 2πrh

T.S.A = 2πr(r+h)

Now,

In T.S.A = 2πrr + 2πrh

462 = 2πrr + 2πrh

462 = 2*22/7*r*r + 154

462 – 154 = 2*22/7*r*r

308*7/2*22 = r*r

49 = r*r

R = 7 cm

Now,

C.S.A = 2πrh

154 = 2*22/7*7*h

154/44 = h

 7/2 =h

H = 3.5 cm or 7/2 cm

Now volume = πrrh

= 22/7 * 7* 7 *7/2

= 11*49

= 539 cm³

I hope it helps……

Answer 2

T.S.A = 3*154 = 462 cm²

C.S.A = 154 cm²

C.S.A = 2πrh

T.S.A = 2πr(r+h)

Now,

In T.S.A = 2πrr + 2πrh

462 = 2πrr + 2πrh

462 = 2*22/7*r*r + 154

462 – 154 = 2*22/7*r*r

308*7/2*22 = r*r

49 = r*r

R = 7 cm

Now,

C.S.A = 2πrh

154 = 2*22/7*7*h

154/44 = h

 7/2 =h

H = 3.5 cm or 7/2 cm

Now volume = πrrh

= 22/7 * 7* 7 *7/2

= 11*49

= 539 cm³

I hope it helps……