In one minute, the metro sells 5 tickets for $3 each, so the earnings from the tickets in one minute are 5 * $3 = $15.
In 6 minutes, the metro will sell an average of 5 tickets per minute * 6 minutes = 30 tickets.
Therefore, the earnings from the tickets in 6 minutes will be 30 tickets * $3 per ticket = $90.
#### 90
The answer is: 90
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
One ticket to the underground costs $3. In one minute, the metro sells an average of 5 such tickets. What will be the earnings from the tickets in 6 minutes?

### Answer:
