Question

Can you please tell me answer​

Answer 1

$\bf \LARGE \color{pink}Hola!$

QuestioN :

$\boxed{ \begin{array}{c} \sf \circ \: \: The \: \: number \: \: of \: \: lines \: \: through \: \: 'n' \: \: collinear \: \: points \\ {\begin{array}{cc} \sf \: a) \: \frac{n(n + 1)}{2}& \sf \:b) \: \frac{n(n - 1)}{2} & \sf \:c) \: \frac{n(n - 1)}{3} & \sf \: d) \: \frac{n(n - 2)}{2} \end{array}}\end{array}}$

AnsweR :

$\rightsquigarrow \underline{ \boxed{ \sf{b )\: \frac{n(n - 1)}{2} }}}$

ExplanatioN :

$\circ \sf \: \: We \: \: can \: \: draw \: \: (n-1) \: \: lines \: \: by \: \: n \: \: pts$

$\: \sf \: \: \: \: hence, \: \: total \: \: number \: \: lines \: \: by \: \: each \: \: pts \: n(n - 1)$

Now,

$\sf \circ \: \: subtracting \: \: double \: \: counted \: \: lines \: \: \frac{n(n - 1)}{2}$

$\sf \dashrightarrow \: {n(n - 1)} - \frac{n(n - 1)}{2}$

$\sf \dashrightarrow \: \underline{ \boxed{ \sf{\frac{n(n - 1)}{2} }}}$

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HOPE THIS IS HELPFUL...

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