Cube root of W means W^(1/3)
question asks what is W^(1/3)???
1. 5th root of w = 64 i.e. W^(1/5) = 64
if we raise both sides to the power of 5 then w = 64^5
sinec we need to find out W^(1/3) now we take the cube root on both sides that gived us W^(1/3) = {(64^5)^(1/3)} or 64^(5/3)
64 can be written as 2^6 so 64^(5/3) = 2^(6^5/3) or 2^10 hence sufficient

2. 15th root of W or w^(1/15) = 4
Raising both sides by 15th power: w = 4^15
Now taking the 3rd root on eavh side: w^(1/3) = 4^5 or 2^10 hence sufficient

Answer D

thank you! makes sense. I did not set it up as an equality which is where problem occured.