A man bought a thousand eggs. He sold twelve dozen eggs and then sold fifteen dozen eggs. How many eggs did he have left?

The man bought a thousand eggs.
Total eggs bought = 1000 eggs.

He sold twelve dozen eggs. Since one dozen equals 12 eggs:
Eggs sold first = $12 \text{ dozen} \times 12 \text{ eggs/dozen}$

He then sold fifteen dozen eggs.
Eggs sold second = $15 \text{ dozen} \times 12 \text{ eggs/dozen}$

Total eggs sold = Eggs sold first + Eggs sold second

Eggs left = Total eggs bought - Total eggs sold

The man had $\boxed{\text{676 eggs}}$ left.