The radius of the sphere decreases at the rate of 6 m/ sec
That is, 
Surface Area of the sphere of radius r is given by 
Differentiating with respect to t,


Answer: a) 8.779 years
b) 8.664 years
<u>Step-by-step explanation:</u>
a)

- A: accumulated amount (balance)
- P: principal amount (original/initial investment)
- r: interest rate (convert to a decimal)
- n: number of times compounded per year
- t: number of years
Given: A = 1800, P = 900, r = 8% = 0.08, n = 3, t = unknown

b)


Good evening ,
Answer:
The graph is a line
Step-by-step explanation:
Look at the photo below for the details.
:)
Answer:
The total money will be $113750(I think)
Just check other's answers.(or use a calculator.)