the annual birth and death rate in a country per 1000 are 39.4 and 19.4 respectively. the number of years q in which the population would be doubled assuming there is no emigration or immigration is
Pick one:
A) q = 20	B) q = 25	C) q = 30	D) q = 35	E) 40
<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">100 - 30</gadget>
<output>70</output>

<gadget id="calculator">39.4 - 19.4</gadget>
<output>20</output>

<gadget id="calculator">20 / 1_000</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">(1/50) * 100</gadget>
<output>2</output>

<gadget id="calculator">70 / 2</gadget>
<output>35</output>

<result>D</result>
the annual birth and death rate in a country per 1000 are 39.4 and 19.4 respectively. the number of years q in which the population would be doubled assuming there is no emigration or immigration is
divide(subtract(const_100, multiply(const_10, const_3)), multiply(divide(subtract(39.4, 19.4), 1000), const_100))
suppose the population of the country in current year is 1000 . so annual increase is 1000 + 39.4 - 19.4 = 1020 hence every year there is an increase of 2 % . 2000 = 1000 ( 1 + ( 2 / 100 ) ) ^ n n = 35 answer is d