Multiple choice

The radii of two right circular cylinders are in the ratio of $2 : 3$ and their heights are in the ratio of $5 : 4$ The ratio of their curved surface areas is

  1. $\displaystyle \dfrac{3}{5}$
  2. $\displaystyle \dfrac{5}{6}$
  3. $\displaystyle \dfrac{4}{5}$
  4. $\displaystyle \dfrac{8}{9}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Curved surface area = 2*pi*r*h. Ratio = (2*pi*r1*h1) / (2*pi*r2*h2) = (r1/r2) * (h1/h2) = (2/3) * (5/4) = 10/12 = 5/6.

AI explanation

Using the formula for the curved surface area of a right circular cylinder, which is 2 * pi * r * h, the ratio of their curved surface areas will be the product of their respective radius and height ratios. We multiply the radius ratio of 2 : 3 by the height ratio of 5 : 4, giving (2 / 3) * (5 / 4) = 10 / 12. By simplifying this fraction, we get 5 / 6.

Keep practicing — related questions