Question

In 2005 for each of the 14 million people present in a country,0.028 were born and 0.008 were died during the year. Using exponential equation the number of people present in 2015 is predicted as

• A. A) 25 millions
• B. B) 17 millions
• C. C) 20 millions
• D. D) 18 millions

Answer 1

The correct option is B B) 17 millions

$\frac{\Delta N}{\Delta T}=rN$

as we know that

$r=b-d$ (b=birth d=death)

$r=0.028-0.008$

$=0.020$

$N=$ initial population $=14$ million

$\frac{\Delta N}{\Delta T}=0.020\times 14$ million

$\Delta T=2015-2005$ year

$=10$ year

$\frac{\Delta N}{10}=2.8$ million

$\Delta N=2.8$ million

$\Delta N=N_f-N_i=2.8$

$N_f=\Delta N+N_i$

$=2.8+14=16.8$ million

$=17$ million