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If 5 pens cost Rs.25, find graphically how many pens can be bought for Rs. 35. Also, find the cost of 3 pens. |
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Answer» Answer: Let cost of one PEN = x cost of one pencil = y 5 pens and 6 pencils cost Rs. 9 ⇒ 5x + 6Y = 9 ....................(1) ⇒ 5x = 9 - 6y ⇒ x = (9-6y)/5 3 pens and 2 pencils cost Rs 5 ⇒3x + 2y = 5 ⇒3(\frac{9-6y}{5} 5 9−6y
) + 2y = 5 ⇒\frac{27}{5} - \frac{18y}{5} +2y = 5 5 27
− 5 18y
+2y=5 ⇒27 -18y +10y = 5*527−18y+10y=5∗5 ⇒27 -8y = 2527−8y=25 ⇒ \begin{lgathered}-8y = 25-27 =-2 \\ y =(-2)/(-8) = 0.25\end{lgathered} −8y=25−27=−2 y=(−2)/(−8)=0.25
x = Cost of one pen = Rs. 1.5 Cost of one Pencil = Rs. 0.25 So cost of one pen and one pencil = 1.5+0.25 = Rs 1.75 |
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