What expression represents a number that is 1/4 as great as 10-2

What is the value of the expression below? (81^2)^1/8

If jaime wants to find 60% of 320, which table should he use?

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.