Question

Planet Earth is 4.5 billion years old and mankind about one hundred and forty thousand years old if we put them in prospective, planet earth's year is one day ( 24 hours) then how many seconds we have lived here on earth?

Answer 1

1 day= 60*60*24seconds=86400 secs
4500000000years=1 day=86400
140000=x
then by ratio and proportions x=140000*86000/4500000000
x=12096000000/4500000000
x=2.688

Answer 2

1 day= (60×60×24)seconds=(3600×24)seconds=86400 seconds.
Now earth years is one day.
or,4500000000years=1 day=86400
A.T.Q.
140000=x
then by ratio and proportions x=140000*86000/4500000000
x=12096000000/4500000000
x=2.688