Let A = {2, 3, 4, . . . , 30} and “∼” be defined on A × A by (a, b) ∼(c, d) iff ad = bc. The number of ordered pairs which are related to (4, 3) is:
Let A = {2, 3, 6, 8, 9, 11}, B = {1, 4, 5, 10, 15}. R on A × B: (a, b) R (c, d) iff 3ad −7bc is even. Then R is:
Among the relations \( S = \left\{(a, b) : a, b \in \mathbb{R} - \{0\},\ 2 + \frac{a}{b} > 0\right\} \) and \( T = \{(a, b) : a, b \in \mathbb{R},\ a^{2} - b^{2} \in \mathbb{Z}\} \),
Let $A=\{-2,-1,0,1,2,3,4\}$. Let $R$ be a relation on $A$ defined by $xRy$ if and only if $2x+y\leq2$. Let $l$ be the number of elements in $R$. Let $m$ and $n$ be the minimum number of elements required to be added in $R$ to make it reflexive and symmetric respectively. Then $l+m+n$ is equal to:
Corner points of the feasible region for an LPP are (0, 2), (3, 0), (6, 0), (6, 8) and (0, 5). Let \(z = 4x + 6y\) be the objective function. The minimum value of z occurs at
In a linear programming problem, the objective function is \(z = 4x + 3y\). The corner points of the feasible region are (0, 8), (2, 5), (4, 3), and (9, 0). Find the minimum value of \(z\).
Consider the following two binary relations on the set \(A = \{a, b, c\}\):\(R_1 = \{(c, a), (b, b), (a, c), (c, c), (b, c), (a, a)\}\) and\(R_2 = \{(a, b), (b, a), (c, c), (c, a), (a, a), (b, b), (a, c)\}\).Then:
In a group of 140 students, 70 opted Mathematics, 46 opted Physics and 28 opted Chemistry. 23 opted both Mathematics and Physics, 9 opted both Physics and Chemistry, 14 opted both Mathematics and Chemistry, and 4 opted all three subjects. The number of students who did not opt for any of the three courses is: