Multiple choice

Series I: 64, 192, 48, 144, 36, 108, 27, 81, 20.25, 60.75 Series II: X, 216, Y, Z, 40.5, W, 30.375, 91.125, P, Q If the roots of a quadratic equation are Z Y and ( X − Y 9 ) , then find the quadratic equation whose variable is r.

  1. r2 + 5r + 6 = 0

  2. r2 + 5r - 6 = 0

  3. r2 - 5r + 6 = 0

  4. r2 - 5r - 6 = 0

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Series II follows multiplication by 3 and division by 4 alternately, giving X = 72, Y = 54 and Z = 162. Interpreting the roots as Z/Y and (X - Y)/9 gives roots 3 and 2, so the equation is r^2 - 5r + 6 = 0.

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