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The vector k ˆ j ˆ 2 i ˆ a      is rotated through a right angle, passing through the y - axis in its way and the resulting vector is b  . Then the projection of b 2 a 3    on k ˆ 3 j ˆ 4 i ˆ 5 c     is

1. 6
2. 3 2
3. 1
4. 2 3

Correct answer: 2 3

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