There are 25 points on a plane of which 7 are collinear . How many quadrilaterals can be formed from these points ?

Deja Bradshaw 2022-10-17 Answered
There are 25 points on a plane of which 7 are collinear . How many quadrilaterals can be formed from these points ?
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Answers (1)

aitorarjolia
Answered 2022-10-18 Author has 11 answers
A quadrilateral is formed by 4 points, where at most 2 may be colinear. Thus, we have
25 C 4  choose four points 7 C 4  subtract out ways to pick four colinear points 7 C 3 18 C 1  subtract out ways to pick three colinear points
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