SSC CGL 2024 PYQ — Question 68

The correct answer is option 2 i.e. 4 : 7.

Given that, ratio of the radii of the bases = 4 : 5

Ratio of heights = 5 : 7

CSA of cylinder = $2\pi rh$

Let the radii of two cylinders be 4x and 5x respectively and heights of the cylinders be 5y and 7y respectively.

According to the given question, the required ratio is,

⇒ ${2 \pi \times 4x \times 5y} \over 2 \pi \times 5x \times 7y$

⇒ $20xy\over 35 xy$ = $4 \over 7$

Hence the required ratio is 4 : 7.