Solve the Equation: 1 + 2 + 3 * 4 - 5

The answer is 10.

To solve this expression, we follow the order of operations (also known as PEMDAS):

1. Parentheses (none in this case)
2. Exponents (none in this case)
3. Multiplication and Division (perform operations from left to right)
4. Addition and Subtraction (perform operations from left to right)

So, first we perform the multiplication operation:

1 + 2 + (3 * 4) - 5

1 + 2 + 12 - 5

Then, we perform the addition and subtraction operations:

15 - 5

= 10