Multiple choice

Ten points are spaced equally around a circle. How many different chords can be formed by joining any 2 of these points? (A chord is a straight line joining two points on the circumference of a circle.)

  1. 36

  2. 45

  3. 18

  4. 90
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The number of chords formed by n points is given by the combination formula nC2. For 10 points, 10C2 = (10 * 9) / 2 = 45.

AI explanation

A chord is formed by joining any two distinct points on the circumference of a circle. With 10 points available, the number of possible chords is the number of combinations of 10 items taken 2 at a time. Using the combination formula, we calculate (10 times 9) divided by (2 times 1), which equals 45.

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