5 pencils and 7 pens together cost Rs. 50, whereas 7 pencils and 5 pens together cost Rs. 46. Find the cost of one pencil and that of one pen.
Answers
Answered by
36
pencil= x
pens= y
ATQ 5x+7y=50 (i)
7x+5y=46 (ii)
multiply (i)(ii) by 7 and 5
35x+49y=350
35x+25y=230
- - -
Subtracting
24y=120
y=5
5x+7(5)=50
5x=50-35
x=25/5=5
x+y
5+5=10Rs
pens= y
ATQ 5x+7y=50 (i)
7x+5y=46 (ii)
multiply (i)(ii) by 7 and 5
35x+49y=350
35x+25y=230
- - -
Subtracting
24y=120
y=5
5x+7(5)=50
5x=50-35
x=25/5=5
x+y
5+5=10Rs
Answered by
36
Answer:
Answer:-
Cost of 1 pencil
Cost of 1 pen
• Given:-
Cost of 5 pencils and 7 pens = Rs. 50
Cost of 7 pencils and 5 pens = Rs. 46
• To Find:-
Cost of 1 pencil and 1 pen = ?
• Solution:-
Let the price of pencil be 'x' and the price of pen be 'y'.
According to the question:-
→
and
→
Multiplying eqn[i] by 5:-
→
→
Multiplying eqn [ii] by 7:-
→
→
Subtracting equation [iii] from [iv]:-
→
→
→
→
→
Substituting value of x in [eqn.i]:-
→
→
→
→
→
→
→
Therefore,
The cost of 1 pencil is Rs. 3
The cost of 1 pen is Rs. 5
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