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2015 AMC 10A Problem 14

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2015 AMC 10A Problem 14AMC 10 Step by Step
Name:                             Date: September 13, 2026
Circles · difficulty 3 of 5 · about 4 min · position P11-15

The diagram below shows the circular face of a clock with radius 2020 cm and a circular disk with radius 1010 cm externally tangent to the clock face at 1212 o'clock. The disk has an arrow painted on it, initially pointing in the upward vertical direction. Let the disk roll clockwise around the clock face. At what point on the clock face will the disk be tangent when the arrow is next pointing in the upward vertical direction?

figure

  1. A)

    2o′clock\mathrm{2 o'clock}

  2. B)

    3o′clock\mathrm{3 o'clock}

  3. C)

    4o′clock\mathrm{4 o'clock}

  4. D)

    6o′clock\mathrm{6 o'clock}

  5. E)

    8o′clock\mathrm{8 o'clock}

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