37 pens and 53 pencils together cost Rs. 320, while 53 pens and 37 pencils together cost Rs. 400. Find the cost of a pen and that of a pencil.

Explanation

To solve the problem, we need to set up a system of linear equations based on the information provided. Let's denote the cost of a pen as \( x \) and the cost of a pencil as \( y \).

### Step 1: Set up the equations
From the problem statement, we can derive the following two equations:

1. For 37 pens and 53 pencils costing Rs. 320:
\[
37x + 53y = 320 \quad \text{(Equation 1)}
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