Fix grammaticality in this sentence: Let's suppose, for xample, that average life span is 80 years.
The average life span of a person is 80 years.

This is a common mistake in English.

• I think the question is a bit unclear. I'm not sure if it's a typo. – user110212 Aug 19 '14 at 19:44
• @user110212: I think the question is unclear. – user110212 Aug 19
The average life span of a person is 80 years.
The average life span of a person is 80 years.
The average life span of a person is 80 years.
The average life span of a person is 80 years.
The average life span of a person is 80 years.
The average life span of a person is 80 years.
The average life span of a person is 80 years.
The average