Question

11. The cost of 4 pens and 4 pencil boxes is 100. Three times the cost of a pen is 15 more
than the cost of a pencil box. Form the pair of linear equations for the above situation.
Find the cost of a pen and a pencil box.
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Answer 1

Answer:

Let number of pens be x, and number of pencil boxes be y.

4x+4y=100

3x=y+15

y=3x-15

4x+4y=100

4x+4(3x-15)=100

4x+12x-60=100

16x=100-60

16x=40

cost of a pen=40paise or 0.40 rupees

cost of a pencilbox= 1.05 rupees

Step-by-step explanation: