Answer:
10
Step-by-step explanation:
Mr. and Mrs. Bailey need to invest $2906.50 so as to send their son to college.
<h3>
Compound interest</h3>
Compound interest is given by:

where A is the amount after t years, P is initial amount, r is the rate and n is the times compounded per period
Given that n = 1, r = 9% = 0.09, A = $7500 t = 11. Hence:

Mr. and Mrs. Bailey need to invest $2906.50 so as to send their son to college.
Find out more on Compound interest at: brainly.com/question/24924853
Answer
After 13.15 years the population of both towns will become equal.
Step-by-step explanation:
Population of the city Anville is given by using the compound interest formula
The formula of compound interest
A = p( 1+r/n)^n*t
using this we get
P1 = 16000 (1 +
) ^1*t
Population of the city of Brinker will be
P2 = 11000( 1 +
) ^1*t
now to make equal population in both towns
P1=P2
16000 (1 +
) ^1*t = 11000( 1 +
) ^1*t

t = 13.15 years