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:
= 18 ( 3 + 2(\sqrt{3} + \sqrt{2} ))
Step-by-step explanation:

Total number of ways to make a pair:
The first player can be any one of 7 . For each of those . . .
The opponent can be any one of the remaining 6 .
Total ways to make a pair = 7 x 6 = 42 ways .
BUT ... every pair can be made in two ways ... A vs B or B vs A .
So 42 'ways' make only (42/2) = 21 different pairs.
If every pair plays 2 matches, then (21 x 2) = <em><u>42 total matches</u></em> will be played.
Now, is that an elegant solution or what !
Add 4x over to 14x, 3=5x2- 18x then add 18x to the other side 3+ 18x= 5x2then divided each side by 5,( 3+18x/5=x2) then square root each side the answer to x would be the square root of 3+18x/5
I counted 72 letters and 17 words so...
72/17 = 4.23 to the nearest whole number: 4 letters per word