Two cylindrical jars have their diameters in the ratio 3:1, but height 1:3. Then the ratio of their volumes is 1:4            (b)  1:3            (c)  3:1         (d)  2:5

Explanation

Let the diameter of two cylindrical jars be 3x and x.

Also, let the height of two cylindrical jars be x and 3x.

So, `r=d/2`

`V^'/V^('')=pi(3x/2)^2x/pi(x/2)^23x`

`V^'/V^('')=(9x^2/4)xx(x)/(x^2/4)xx3x`

`V^'/V^('')=3/1`

Required ratio is `3:1`

Hence, option(c) is correct.