ASSERTION-REASON BASED QUESTIONS:-
Questions number 19 and 20 are Assertion and Reason based questions.
Two statements are given, one labelled Assertion (A) and the other labelled Reason (R).
Select the correct answer from the codes (A), (B), (C) and (D) as given below.
Step 1: Analyze Assertion (A)
For \( R \) to be reflexive, \( (x, x) \) must belong to \( R \) for all \( x \in \mathbb{N} \). This means \( x + x = 2x \) must be a prime number.
However, for \( x>1 \), \( 2x \) is not a prime number as it is divisible by \( 2 \).
Therefore, \( R \) is not reflexive, and Assertion (A) is true.
Step 2: Analyze Reason (R)
The Reason states that \( 2n \) is composite for all \( n \).
This is false because when \( n = 1 \), \( 2n = 2 \), which is a prime number.
Therefore, Reason (R) is false.
Step 3: Conclusion
Since Assertion (A) is true and Reason (R) is false, the correct answer is option (C).
Assertion (A): The corner points of the bounded feasible region of a L.P.P. are shown below. The maximum value of \( Z = x + 2y \) occurs at infinite points.
Reason (R): The optimal solution of a LPP having bounded feasible region must occur at corner points.
Step 1: Analyze Assertion (A)
From the graph, the line \( Z = x + 2y \) passes through two corner points \( (60, 0) \) and \( (120, 60) \), providing the same maximum value. This indicates that the maximum value occurs at infinite points along this segment.
Thus, Assertion (A) is true.
Step 2: Analyze Reason (R)
In general, the optimal solution of an LPP occurs at corner points of the feasible region. This is true; however, in this case, the solution lies along a line segment connecting two corner points.
Thus, Reason (R) is not the correct explanation of Assertion (A).
Step 3: Conclusion
Both Assertion (A) and Reason (R) are true, but Reason (R) does not explain Assertion (A).
Hence, the correct answer is option (B).
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:
Rohit, Jaspreet, and Alia appeared for an interview for three vacancies in the same post. The probability of Rohit's selection is \( \frac{1}{5} \), Jaspreet's selection is \( \frac{1}{3} \), and Alia's selection is \( \frac{1}{4} \). The events of selection are independent of each other.
Based on the above information, answer the following questions:
An instructor at the astronomical centre shows three among the brightest stars in a particular constellation. Assume that the telescope is located at \( O(0,0,0) \) and the three stars have their locations at points \( D, A, \) and \( V \), having position vectors: \[ 2\hat{i} + 3\hat{j} + 4\hat{k}, \quad 7\hat{i} + 5\hat{j} + 8\hat{k}, \quad -3\hat{i} + 7\hat{j} + 11\hat{k} \] respectively. Based on the above information, answer the following questions: