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MHT CET20228 Aug 2022Evening ShiftMathematicsVector AlgebraActual

If the vector a =2 i +2 j +3 k , b =- i +2 j + k and c =3 i + j are such that ( a + b ) is perpendicular to c , then the value of is

Options

  1. A-8
  2. B10
  3. C8
  4. D8 3

Correct answer

C. 8

Step-by-step solution

aligned & a + b c & ( a + b ) c =0 & (2 i +2 j +3 k )+ (- i +2 j + k ) (3 i + j )=0 & (2- ) i +(2+2 ) j +(3+ ) k (3 i + j )=0 & (2- ) 3+(2+2 ) 1+(3+ ) 0=0 & =8 aligned

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