Answer:
Step-by-step explanation:
Given that in 1987, the population of country A was estimated at 87 million people, with an annual growth rate of 3.5%
Thus the equation for population for country A would be

The 1987 population of country B was estimated at 243 million with an annual growth rate of 0.6%.
So equation for population for country B would be
where t = time in years and P in millions
a) P(A) = 2*87 when

Take log and solve
ln 2 = 0.005 t
t = 138.63
Thus after 138 years population will double for A
b) P(A) = P(B) when

Approximately after 35.5 years the populations of both countries would be equal.
Answer:
The sum of 8 geometric sequence is 959780
Step-by-step explanation:
We are given
this sequence is geometric
-4 , 24 , -144
First term is -4
so, 
now, we can find common ratio

we can use formula

n=8
now, we can plug values

now, we can simplify it
and we get

Answer:
5 x 8 /a*7
Step-by-step explanation:
Answer: 179.93
Step-by-step explanation:
The shadow of the tree is about 17.955 feet long.