MCQ
In a triangle $ ABC$ , if $2\overrightarrow {AC} = 3\overrightarrow {CB} ,$ then $2\overrightarrow {OA} + 3\overrightarrow {OB} $ equals
  • $5\overrightarrow {OC} $
  • B
    $-\overrightarrow {OC} $
  • C
    $\,\overrightarrow {OC} $
  • D
    None of these

Answer

Correct option: A.
$5\overrightarrow {OC} $
a
(a) $2\overrightarrow {OA} + 3\overrightarrow {OB} = 2(\overrightarrow {OC} + \overrightarrow {CA} ) + 3\,(\overrightarrow {OC} + \overrightarrow {CB} )$

$ = 5\overrightarrow {OC} + 2\overrightarrow {CA} + 3\overrightarrow {CB} = 5\overrightarrow {OC} $, .$\{ \because \,2\overrightarrow {CA}  =  - 3\overrightarrow {CB} \} $

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