Question 2
How many polynomials of degree $5$ with the coefficients being $1$ or $-1$ have a root at $1$?
(A) $5$
(B) $10$
(C) $15$
(D) $20$
(E) $24$
(A) $5$
(B) $10$
(C) $15$
(D) $20$
(E) $24$
MathNet 2012 Question 2
Math Olympiad Vault · MathNet 2012