A pen and a pencil cost Rs. 12. Three pencils and five pens cost Rs. 56. Find the cost of one pen
and one pencil.

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10 and 2

2 and 11

4 and 12

3 and 4

answer is A.

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Detailed Solution

Concept- Using the addition method, we will also solve simultaneous equations. By multiplying both equations in the question by the correct constants, we attempt to make one of the variable’s coefficients equal in both. Then, to create a linear equation with one variable, simply subtract any equation from any other equation.
Let us consider the cost of one pen and one pencil is x and y respectively.
It is given that the cost of three pencils and five pens is Rs. 56
According to the question, we have
Question Image

Now we will solve the equations 1 and 2 by substituting equation 1 in equation 2, we get
Question Image

Further, we will substitute the value of y in equation (1), we get

As a result, the cost of one pen is 10 rupees and that of one pencil is 2 rupees.
Hence, the correct answer is option (1).

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