AMC 8 Daily Practice - The Sum of a Finite Arithmetic Series

Complete problem set with solutions and individual problem pages

Problem 1 Easy

A town hall clock chimes the hour number on every full hour and once on every half-hour. How many chimes will occur in a full 24-hour period?

  • A.

    24

  • B.

    90

  • C.

    156

  • D.

    180

  • E.

    270

Answer:D

Daily chimes:   2 \times \left(1+2+3+\cdots+12+ 12 \right) = 2 \times [ \frac{12 \times \left(1+12\right)}{2} + 12 ] = 180