Question

let ab, cd, ef, gh, and jk be five diameters of a circle with center at o. in how many ways can three points be chosen out of a, b, c, d, e, f, g, h, j, k, and o so as to form a triangle?

Answer 1

Thank you for asking this question. Here is your answer:

Permutation and Combination, we can see that,

There are 11 points from which a triangle can be formed. But there are 5 lines which have 3 points linearly.

Number of triangles formed = 11C3 – 5 (because of the lines)

165 – 5 = 160 triangles

Answer: 160

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