The correct answer to this question is One-third. When it comes to the age of the universe in the amount of years, it is estimated that Earth is over billions years old. It is approximately 4 billion years old. Unfortunately, we have not been able to get the exact age of Earth.
However, scientists are still working to try and find the exact time that the Earth has been around, by finding the oldest rock that is on Earth. Earth is expected to be around for millions of more years, if not longer. However, studies have shown that there are other habitable planets where humans can live.
Layers in glaciers demonstrate the world's history that is much longer than 10,000 years and radiometric, which shows that the earth was formed at around 4.5 billion years. Light from the galaxies is reaching us billions of years after it left, and the expansion rate of the universe dates its age to 13.8 billion years. 4.5 billion years is the same age as the rest of the planets in the solar system and the sun.
Studies of radioactive elements quantify the age of the earth. Another system of measurement is based on the rate of expansion of the universe. By measuring the distance to remote galaxies and the speed at which they are moving away from us. Astronomers can determine how much time the galaxies have required to get as far away as they are, which tells how long the universe has been expanding or how old it is.