Volumes of revolution CP1 question

https://preview.redd.it/mh9xxx8tif0d1.png?width=901&format=png&auto=webp&s=4539c486f86d4f5d40a265d00e422be2777df6f6

I'm doing this question from a Madas paper, but get the volume as 512pi/15 - not sure what I'm doing wrong?

Thanks