SOLUTION: saima bought 2 black pencils and three red pencils for Rs.23. after a week she bought 3 black pencils and 2 red pencils.if price of pencils remained same for both transactions, how

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Question 824684: saima bought 2 black pencils and three red pencils for Rs.23. after a week she bought 3 black pencils and 2 red pencils.if price of pencils remained same for both transactions, how muchshe paid for one black pencil?
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
saima bought 2 black pencils and three red pencils for Rs.23. after a week she bought 3 black pencils and 2 red pencils.if price of pencils remained same for both transactions, how muchshe paid for one black pencil?
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Equations:
2b + 3r = 23
3b + 2r = 23
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Modify for elimination:
4b + 6r = 2*23
9b + 6r = 3*23
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Subtract and solve for "b":
5b = 23
b = 4.60 Rs
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Cheers,
Stan H.
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