Question

If the average life of a person is taken as $100S$ the age of the universe on this scale is of the order

• A. ${10}^{10}s$
• B. ${10}^{8}s$
• C. ${10}^{17}s$
• D. ${10}^{9}s$

Answer 1

The correct option is A ${10}^{10}s$

$\frac{fifteensec}{lifetime}=\frac{100year}{universeage}$
$\frac{15}{100}=\frac{100\times 12\times 30\times 24\times 60\times 60}{universeage}$
universe age $=2.07\times {10}^{10}$
So order $={10}^{10}$