The length of the plastic tube of the refill of a dot pen is `(12.7+-0.1)` cm and the length of the metal nib is `(1.40+-0.2)cm`. What is the total length of the refill?

Explanation

To solve the problem of finding the total length of the refill of a dot pen, we will follow these steps:

### Step 1: Identify the lengths and their uncertainties
We have two measurements:
- Length of the plastic tube: \( L_1 = 12.7 \, \text{cm} \) with an uncertainty of \( \Delta L_1 = 0.1 \, \text{cm} \)
- Length of the metal nib: \( L_2 = 1.40 \, \text{cm} \) with an uncertainty of \( \Delta L_2 = 0.2 \, \text{cm} \)

### Step 2: Calculate the total length
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