Perform the indicated operation
1/15abc (5a^3b^5c^2)
1/(15abc)*(5a^3*b^5*c^2).
When you divide, you subtract exponents.
You have an a^1*b^1*c^1 in the denominator, and a^3*b^5*c^2 in the numerator.
Subtract exponents, and you are left with a^2*b^4*c in the numerator.
5/15 = 1/3, so your final answer is a^2*b^4*c/3