Answer:
(b) x^15/y^5
Explanation:
The exponent outside parentheses multiplies all of the exponents inside parentheses.
(x^3/y)^5 = x^(3·5)/y^(1·5) = x^15/y^5
______
Additional comment
When it comes to exponents, I find it useful to remember that an exponent signifies repeated multiplication: x·x·x = x³. The exponent outside parentheses has the same meaning:
(x³)² = (x·x·x)·(x·x·x) = x⁶
The rule is summarized by ...
(a^b)^c = a^(bc)