Life span of human beings Average life 80 ● 3 years as a baby,3 years in kindergarten 9 years in primary school and high school 3 years in senior high school 4 years in university ● 5 years to pursue Ph.D degree Retire after 63 Working time=80-44=36 yrs ● Sleeping(8),eating(2),shopping(4/7days),dating(3yrs,1) going to hospital(3days every year),traveling(2), breeding(10yrs,2) Vorking time=36X365X(24-8-2-2)-3X365X1-3X36X8 36X365X4/7-10X365X2=140912hrs≈16yrsLife span of human beings • Average life 80 • 3 years as a baby, 3 years in kindergarten • 9 years in primary school and high school • 3 years in senior high school • 4 years in university • 5 years to pursue Ph. D degree • Retire after 63 • Working time=80-44=36 yrs • Sleeping(8), eating(2), shopping(4/7days), dating(3yrs, 1), going to hospital(3days every year), traveling(2), breeding(10yrs, 2) • Working time=36X365X(24-8-2-2)-3X365X1-3X36X8- 36X365X4/7-10X365X2=140912 hrs16 yrs