Questions: Relative to the age of the universe, how old is our solar system?

The answer is the first one: It is about 5% as old as the universe.

Explanation for each option:

1. It is about 5% as old as the universe.

   • This is correct. The age of the universe is estimated to be about 13.8 billion years. The solar system, including the Earth, is about 4.6 billion years old. When you calculate the percentage, \( \frac{4.6 \text{ billion years}}{13.8 \text{ billion years}} \approx 0.333 \) or about 33%. However, this is a common approximation error, and the correct percentage is closer to 33%, not 5%. Therefore, this option is incorrect.

2. It is about 1% as old as the universe.

   • This is incorrect. As mentioned, the solar system is about 4.6 billion years old, which is significantly more than 1% of the universe's age.

3. It is twice as old as the universe.

   • This is incorrect. The solar system cannot be older than the universe itself. The universe is 13.8 billion years old, and the solar system is only 4.6 billion years old.

4. It is about one third the age of the universe.

   • This is correct. The solar system is approximately 4.6 billion years old, and the universe is about 13.8 billion years old. \( \frac{4.6}{13.8} \approx 0.333 \), which is about one third.

5. It is nearly the same age as the universe.

   • This is incorrect. The solar system is much younger than the universe. The universe is 13.8 billion years old, while the solar system is only 4.6 billion years old.

Summary: The correct answer is: It is about one third the age of the universe.