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There are 2 methods Given: b( birth rate)=39.4/1000, d(death rate)= 19.4/1000 b-d= 39.4-19.4=20/1000 (i.e.0.02=2%) P( population) = 2P( population) To find: n=? Solution :Let's assume P=1000 applying formula: An= p(1+i)^n Putting values: 2000=1000(1+0.02)^n 2=1.02^n n=35 years. Alternative(short method) : the Rule of 70 which is a simple way to calculate the approximateÂ number of years it takes for the level of a variable growing at a constant rate to double. This rule states that the approximate number of years n for a variable growing at the constant growth rate of RÂ percent, to double is n = 70/R Since B-D = 39.4-19.4 = 20 normalized to 1000 = 2% The n = 70/2 = 35

Is rule 70 is applicable to ca foundation level

You can always use rule of 69,70 or 71 to approximate the answer.

You can always use rule of 69,70 or 71 to approximate the answer.

where this rule available sir is this was taught in videos sir

Is rule 70 is applicable to ca foundation level

Basically its is "rule of 72" is simple way to determine how long will ur investment 'double' given in fixed annual rate..but i used 70 in this sum for just convenience thats it. Remember if something increase in fixed annual rate(R) and u required to find a time(N) in certain interest to take the value double. U can use "rule of 72" for to get aprox answer N=72/R