Question

How many years would it take to spend one Avogadro’s number of rupees at a rate of 10 lakh of rupees in one second?

• A. $8.65\times {10}^{18}$
• B. $1.91\times {10}^{10}$
• C. $6.023\times {10}^{15}$
• D. $3.81\times {10}^4$

Answer 1

The correct option is B $1.91\times {10}^{10}$

Rate of money spent = 10 lakh rupees per second = $\text{Rs}{10}^6/s$
Now, Avogadro’s number of rupees will be spent in = $\frac{\text{Avagadro's number}}{\text{Rate of money spent per sec}}\text{s}$
$=\frac{6.023\times {10}^{23}}{{10}^6}=6.023\times {10}^{17}\text{s}$
$1\text{year}=365\text{days}=365\times 24\text{hours}=365\times 24\times 3600=3.15\times {10}^7\text{seconds}$
Therefore, number of years $=\frac{6.023\times {10}^{17}}{3.15\times {10}^7}=1.91\times {10}^{10}\text{years}$