Question

A man was born during a year in which the Johnson comet was visible in the sky. The next time that the comet was visible after man's birth year was in 2005. in what year was the man born?

Answer 1

The man was born in 1967.

Step-by-step explanation:

The Johnson comet, also known as Comet Halley, has a periodic orbit around the Sun, appearing every 74 to 79 years. The last time the comet was visible before 2005 was in 1986. We can calculate when the man was born by subtracting the comet's periodic orbit from 2005.

2005 - (1986 - x) = 0

Simplifying the equation, we get:

x = 2005 - 1986 = 19

So, the man was born 19 years before the last appearance of the Johnson comet, which was in 1967.

Answer 2

We can see in the table that the Johnson comet is visible once in each period of 7 years.

So if the comet was visible in 2005, the previous year that the comet was visible is 7 years before, that is:

2005 - 7 = 1998

So the man was born in 1998.