f(1) = p^5 + q^3 + rsud21 wrote:
(1) f(-1) = 1
f(-1) = -p^5 - q^3 - r = -(p^5 + q^3 + r)
f(-1) = 1 implies -(p^5 + q^3 + r) = 1 or p^5 + q^3 + r = -1
So, f(1) = -1; SUFFICIENT.
(2) pqr > 0 but we do not know the values of p, q, and r; NOT sufficient.
The correct answer is A.
