The age of the universe is about `10^17` years whereas the mankind has existed for `10^9` years. For how many seconds would the man have existed if the age of universe were 1 day ?

Explanation

`"The age of the universe"/"The age of the mankind"=10^17/10^9=10^8`
According to new scale, the age of universe = 1 day = 86400 s . If the age of man =x
Again the ratio of the two should be `10^8`
`therefore 86400/x=10^8`
`rArr x=86400/10^8=8.64xx10^(-4)` s