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If one root of the quadratic equation x² - 3x + k = 0 is double the other, what is the value of k?

Answer: B. 1
Let the roots be r and 2r. Then, r + 2r = 3r = 3, so r = 1. The product of the roots is r(2r) = 2r² = k, thus k = 2(1)² = 2.
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