Question

Age of the universe is about $10^{10} yr$, whereas the mankind has existed for $10^{6} yr$. For how many seconds would the man have existed, if age of universe were $1$ day?

• A. 9.2 s
• B. 10.2 s
• C. 8.6 s
• D. 10.5 s

Answer 1

Answer: (C)

Given, age of mankind $=10^{6} yr$
and age of universe $=10^{10} yr$
Magnification in time $=\frac{\text { Age of mankind }}{\text { Age of universe }}=\frac{10^{6}}{10^{10}}=10^{-4}$
$ \therefore $ Apparent age of mankind
$=10^{-4} \times 1 $ day $=10^{-4} \times 86400 \,s $
$=8.64 s \approx 8.6\, s $