Three shopkeepers A, B, C go to store to buy stationary. A purchases 10 dozen pens, 6 dozen pencils. B purchases 10 dozen notebooks, 5 dozen pens and 7 dozen pencils. C purchases 11 dozen notebooks and 13 dozen pens. A notebook costs 40 paise, a pen costs 1.25 rupees and pencil costs 35 paise. Identity correct statements: (A) If P is quantity matrix (stationary purchased by A, B, C) then order of P is $2×3$ (B) If Q is a price matrix then order of matrix Q is $(3×1)$, to get individual bills (C) Q is $\begin{bmatrix} 0 & 10 & 6\\10 & 5 & 7\\11 & 13 & 0 \end{bmatrix}$ (D) Q is [0.40 1.25 0.35 ] (E) Matrix P is $ \begin{pmatrix}0& 120& 72\\120 & 60& 84\\132 & 156 & 0 \end{pmatrix}$ Choose the correct answer from the options given below : |
(A), (D) Only (B), (D) Only (C), (A) Only (B), (E) Only |
(B), (E) Only |
The correct answer is Option (4) → (B) Only Let pens be $x$, pencil be $y$ and notebooks be $z$. $A → 10x+6y$ $B → 5x+7y+11z$ $C → 13x+11z$ $⇒P=\begin{bmatrix}10&6&0\\5&7&11\\13&0&11\end{bmatrix}_{3×3}$ $Q=\begin{bmatrix}0.35\\1.25\\0.40\end{bmatrix}_{3×1}$ ∴ Q is of order 3×1. |