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Question
Jay and Ram are two friends in a class. Jay wanted to buy 4 pens and 8 notebooks, Ram wanted to buy 5 pens and 12 notebooks. Both of them went to a shop. The price of a pen and a notebook which they have selected was Rs.6 and Rs.10. Using Matrix multiplication, find the amount required from each one of them
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Solution
Let A be the matrix of pens and notebooks and B be the matrix of prices of one pen and one notebook.
∴ A = `[("Pens", "Notebooks"),(4, 8),(5, 12)]"Jay"/"Ram"`
and B = `[(6),(10)]"Pens"/"Notebooks"`
The total amount required for each one of them is obtained by matrix AB.
∴ AB = `[(4, 8),(5, 12)] [(6),(10)]`
= `[(24 + 80),(30 + 120)]`
= `[(104),(150)]`
∴ Jay needs ₹ 104 and Ram needs ₹ 150.
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