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If 0 c b b r , k ˆ 4 j ˆ 3 i ˆ 7 c , k ˆ j ˆ i ˆ b , k ˆ 2 i ˆ a                     and 0 a . r    . Then c . r   is equal to

1. 32
2. 30
3. 34
4. 36

Correct answer: 34

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