For a cone, if the radius was quadrupled and the slant height was reduced to one sixth of its original size, what would be the formula to find the modified surface area?

The correct answer for the question that is being presented above is this one: 

First, we need to know the surface area of the cone:
Surface Area = pi * r * hs + pi * r^2 

radius= 4x * hs = 1/6 x 

modified area=2PI*hs/3 + PI (16)r^2 where r, hs are the original slant heights, and radius.

let me know is it correct. hope it helps