Question

According to modern​ science, Earth is about 4.5 billion years old and written human history extends back about​ 10,000 years. Suppose the entire history of Earth is represented with a 100-meter-long ​timeline, with the birth of Earth on one end and today at the other end. a. What distance represents 11 billion​ years? b. How far from the end of the timeline does written human history​ begin?

Answer 1

I believe the answer to A. is 244.44 meters long.  100 meters equals earth's timeline of 4.5 billion.  11 divided by 4.5 billion equals 2.4444.  Multiply by 100 for the meters and you get 244.44 meters.

Answer 2

A- The distance that represents 11 billion years is 244.4 meters.

B- Written human history begins 0.2 milimeters far from the end of the timeline.

Explanation:

A- We can solve this problem by using crossed multiplication.

4,5 billion years --- 100 meters

11 billion years --- X

11 x 100 / 4,5 = X

X= 244.4

B- Once again, this can be solved using crossed multiplication.

If 4,500,000,000 years are represented in 100 meters, that would be:

4,500,000,000 --- 100 meters

10,000 --- X

10,000 x 100 / 4,500,000,000 = X

X= 0.0002 meters

0.0002 meters are 0.2 milimeters