Question

Cylinder A has a radius 2 cm and a height of 4 cm. Cylinder B has a radius 1 cm and a height of 5 cm. Which cylinder has the greater surface area? (use $\pi =3.14$).

• A. Cylinder A is lesser than B
• B. Cylinder A and B
• C. Cylinder B
• D. Cylinder A

Answer 1

The correct option is D Cylinder A

Surface area of cylinder is $A=2\pi r(r+h)$

Since, cylinder A has radius $r=2$ cm and height $h=4$ cm.

Thus,

$A=2\pi r(r+h)=2\times 3.14\times 2(2+4)=12.56\times 6=75.36$

Therefore, the surface area of cylinder A is $75.36$ cm${}^2$.

Also, cylinder B has radius $r=1$ cm and height $h=5$ cm.

Thus,

$A=2\pi r(r+h)=2\times 3.14\times 1(1+5)=6.28\times 6=37.68$

Therefore, the surface area of cylinder B is $37.68$ cm${}^2$.

Hence, cylinder A has greater surface area.