The population of a given community of birds after 3 years

Arithmetic and Geometric progressions.

The population of a given community of birds after 3 years

Postby promise » Wed Feb 21, 2018 3:33 am

The population of a given community of birds after 3 years is 3million after 6years the population became 81million what is their first year population what is their 11th year population please help
promise
 
Posts: 1
Joined: Wed Feb 21, 2018 3:24 am
Reputation: 0

Re: The population of a given community of birds after 3 yea

Postby Guest » Wed Feb 21, 2018 1:22 pm

It is a geometric progression with common ratio 3. third year the population was $ a_1q^2$

$a_13^2 =3$
$a_1 =3/9 million=1/3 million$

eleventh year was $\frac13*3^{10}$
Guest
 


Return to Progressions, Series



Who is online

Users browsing this forum: No registered users and 1 guest