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How many chords can be drawn from 12 points in a circle |
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Answer» Number of points = 21Hence n = 21A chord connects circle at 2 pointsHence, r = 2Number of chord from 21 points = nCr = 21C2= 21!/2!(21−2)= 21!/(2! 19! )= (21 × 20 × 19!)/((2 × 1) × 19!)= (21 × 20)/(2 ) = 210 chords. Ans: 12C2 = 66 chords. |
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