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 $=10^{-4}\times 86400s$
$=8.64s\approx 8.6s$