Question

Mankind has existed for about ${10}^6$ years whereas the universe is about ${10}^{10}$ years old. If the age of universe is taken to be one day, for how many seconds has the mankind existed?

• A. 10 sec
• B. 8 sec
• C. 8.64 sec
• D. 64 sec

Answer 1

The correct option is C 8.64 sec

Age of universe $={10}^{10}year=1day$

Age of mankind $={10}^{6}year$

So, ${10}^{6}year=\frac{{10}^6}{{10}^{10}}={10}^{-4}day$

${10}^{-4}={10}^{-4}\times 24\times 3600=8.64sec$