Given that the sun is estimated to be about five billion years old, scientists estimate that we are about halfway through its lifetime. this means that the sun’s lifetime is expected to be what length of time?
1. 10 billion years
2. 5 billion years
3. 20 billion years
4. 5 billion years

(A) 10 Billion Years

Explanation:

The sun is about 5 billion years old. We are about halfway through its lifetime.

The sun's lifetime is expected to be ___ length of time.

We must add 5 to 5 because 5 is one half of its lifetime and also the other half

5 + 5 = 10

The suns lifetime is expected to be 10 billion years old.