How many buckets of paint are needed to paint Moscow?

This question is a classic example of an estimation problem. An exact answer is impossible without data, so it's important to demonstrate the approach to solving it.

1. Estimate the area of Moscow. For example, about 2,500 km² (2,500,000,000 m²).

2. Estimate the area covered by one bucket of paint. For example, a 10-liter bucket covers about 80 m² (depends on the type of paint).

3. Divide the total area by the area covered by one bucket:

   2,500,000,000 m² / 80 m² ≈ 31,250,000 buckets.

4. Consider that not the entire area needs painting—many are parks, roads, etc. Assume only 10% of the area needs painting.

   Then: 3,125,000 buckets.

5. Also consider the number of paint layers, surface type, and losses.

Thus, the answer is on the order of several million buckets, but the main point is to show a logical approach to estimation.