Convert and Add: Solving 1.1L + 1500mL Water Volume Problem

To solve this problem, we'll follow these steps:

• Step 1: Convert milliliters to liters.
• Step 2: Add the liters together.

Now, let's work through each step:
Step 1: Convert 1500 milliliters to liters. Since 1 liter = 1000 milliliters, we have: $\frac{1500}{1000} = 1.5$ liters.
Step 2: Add 1.1 liters and 1.5 liters:
$1.1 + 1.5 = 2.6$ liters.

Therefore, the total amount of water Peter drank is $2.6$ liters.