ska7945 wrote:i think you misunderstood the Qs.
i asked how you solve x^15=4
just like A, 2^5=64
so anybody?

The question is not asking you to solve x^15 = 4. It says that the 15th root of x (well, it says w, but I'll use x) is 4, so you would be solving:

x^(1/15) = 4

which is what pranavc has already done. In more detail- raise both sides to the power 15, and you have

x = 4^(15) = (2^2)^(15) = 2^(30)

The cube root of x is equal to x^(1/3). Since x = 2^(30),

x^(1/3) = (2^(30))^(1/3) = 2^(10) = 1028

Of course, as Suyog pointed out, it's a Data Sufficiency question, so there's no advantage to actually solving the question. As soon as you see you'll get a single numerical answer for x, you can stop working.

Incidentally, if the question did ask you to solve

x^15=4

then x would be equal to 4^(1/15). You can't write that any more simply.