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Let → a be a vector which is perpendicular to the vector k ˆ 2 j ˆ 2 1 i ˆ 3 + + . If k ˆ 4 j ˆ 13 i ˆ 2 ) k ˆ i ˆ 2 ( a − − = + × → , then the projection of the vector → a on the vector k ˆ j ˆ 2 i ˆ 2 + + is -

1. 3 1
2. 1
3. 3 5
4. 3 7

Correct answer: 3 5

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