The radius of a come is multiplied by 1.6 to create a radio is of a new cone with the same height . the volume of the new cone is what?

Let's call the initial radius r1 and the second radius is r2. And we know that r2=1.6 * r1.
The volume of the first cone can be calculated by V = π * r1^2 * h /3
The volume of the second cone can be calculated by V = π * r2^2 * h /3

If we replace r2 by using r2=1.6 * r1 then we get:
V = π * (1.6*r1)^2 * h /3
or V = π * 2.56(r1)^2 * h /3

And so we see that the volume of the second cone is now 2.56 times bigger than the first