[Ans] Which Country Has The Longest Life Expectancy In The World?

What is the Life expectancy ?

Life expectancy equals the average number of years a person born in a given country is expected to live if mortality rates at each age were to remain steady in the future. 

As of 2014, the country with the highest life expectancy is Monaco at 89.52 years; the country with the lowest life expectancy is Chad at just 49.81 years.

Source : https://www.infoplease.com/world/health-and-social-statistics/life-expectancy-countries-0

As per the  wikipedia following is the list of Countries with descending order of life span of human.

 Japan

  Switzerland

 Singapore

 Australia

 Spain

 Iceland

 Italy

 Israel

 Sweden

 France

Comparing life expectancies from birth across countries can be problematic. Worldwide, the average life expectancy at birth was 71.0 years (68 years and 6 months for males and 73 years and 6 months for females) over the period 2010–2013 according to United Nations World Population Prospects 2012 Revision.

Continue the further reading with below link.

https://en.wikipedia.org/wiki/List_of_countries_by_life_expectancy