A company sells pens, notebooks and files in two cities. Its sales are $S = \begin{bmatrix}200 & 150 & 100 \\ 120 & 250 & 90\end{bmatrix}$ , with row 1 for Agra, row 2 for Bhopal, and the columns in that order. The prices are ₹5, ₹4 and ₹10. Using $SP$ with $P = \begin{bmatrix}5 \\ 4 \\ 10\end{bmatrix}$ , what is the revenue from Bhopal, in rupees?

460

Correct answerYour answer

2{,}500

Correct answerYour answer

2{,}600

Correct answerYour answer

5{,}100

Correct answerYour answer

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CorrectNot quiteAnswer B

Correct answer: B

$SP$ is a 2 × 1 matrix: each row of $S$ times the price column gives that city's revenue.
Bhopal: $120(5) + 250(4) + 90(10) = 600 + 1{,}000 + 900 = 2{,}500$ .

Worth noting

2,600 is Agra's revenue, row 1 of $SP$ .

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Explanation