Cost of 2 pens, 5 pencils and 7 erasers is 37 rupees.Cost of 7 pens, 1 eraser and 2 pencils is 49 rupees.What is the cost of 9 pencils and 47 pens?*
Question
Cost of 2 pens, 5 pencils and 7 erasers is 37 rupees.
Cost of 7 pens, 1 eraser and 2 pencils is 49 rupees.
What is the cost of 9 pencils and 47 pens?
Solution
The problem can be solved using the method of simultaneous equations. Let's denote the cost of a pen as P, the cost of a pencil as C, and the cost of an eraser as E.
From the problem, we have the following two equations:
2P + 5C + 7E = 37 (equation 1)
7P + 2C + E = 49 (equation 2)
We can solve these equations to find the values of P, C, and E.
First, let's multiply equation 2 by 7 and subtract equation 1 from it:
49P + 14C + 7E - 2P - 5C - 7E = 343 - 37
This simplifies to:
47P + 9C = 306
So, the cost of 47 pens and 9 pencils is 306 rupees.
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