Multiple choice

The ratio between the radius of the base and height of the cylinder is $2:3$. If the volume is $12936 cm^{3}$, what is the total surface area of the cylinder?

  1. $3080 cm^{2}$
  2. $3000 cm^2$
  3. $4000 cm^2$
  4. $4050 cm^2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

r:h = 2:3, so r=2k, h=3k. Volume = pi*r^2*h = (22/7)(4k^2)(3k) = 12936. (264/7)k^3 = 12936. k^3 = 12936 * 7 / 264 = 343. k = 7. r=14, h=21. Total Surface Area = 2*pi*r(r+h) = 2*(22/7)14(14+21) = 2*22*2*35 = 3080.

AI explanation

Let the radius be $2x$ and the height be $3x$. The volume of a cylinder is $\pi r^2h$, so we have $(22/7) \times (2x)^2 \times (3x) = 12936$. This simplifies to $264x^3/7 = 12936$, which means $x^3 = 343$ and $x = 7$. The radius is $14$ cm and the height is $21$ cm. The total surface area formula is $2\pi r(r + h)$, which gives $2 \times (22/7) \times 14 \times (14 + 21) = 3080$ cm$^2$. The total surface area is 3080 cm$^2$.