Answer :
a) 13000 divided by 2 is 6500, which was the population 10 years ago. 6500 divided by 2 is 3250, which was the population 20 years ago. 3250 divided by 2 is 1625, which was the bird population 30 years ago. 25 is halfway between 20 and 30, and 2437.5 is halfway between 3250 and 1625, so I would say that 2437.5 is the answer.
b) Well 13000 times 2 gives you 26000, which would be in ten ears, and halfway between 13000 and 26000 is 19500, which gives you the bird population in five years. :-)
Answer:
Step-by-step explanation:
Initial population = x
Population after 25years = 13000
If the population doubles every 10 years then the initial population would be 1/6 of the current population. Example 1+1=2; 2+2=4; 4+4=8; 8+4/2 =6
That is first 10years population doubles, second 10 years it also doubles then the next 5years it is
( population + 1/2 of population)
Therefore the initial population will be
=13000/6
=2166.67
Approximately 2166
B) 5 years from now the birds population will be
13000+(0.5*13000)
=19500