A store has been selling calculators at Rs. 350 each. A market survey indicates that a reduction in price (\( p \)) of calculators increases the number of units (\( x \)) sold. The relation between the price and quantity sold is given by the demand function:
\[ p = 450 - \frac{x}{2}. \]
Based on the above information, answer the following questions:
If vector \( \mathbf{a} = 3 \hat{i} + 2 \hat{j} - \hat{k} \) \text{ and } \( \mathbf{b} = \hat{i} - \hat{j} + \hat{k} \), then which of the following is correct?