SOLUTION: The area of a large puddle is evaporating at the rate 25% each hour. At 12:00 noon the diameter of the puddle was 3.02 meters. A. Complete the table below.( hint: if 25% evapora

Algebra ->  Equations -> SOLUTION: The area of a large puddle is evaporating at the rate 25% each hour. At 12:00 noon the diameter of the puddle was 3.02 meters. A. Complete the table below.( hint: if 25% evapora      Log On


   

Question 113896: The area of a large puddle is evaporating at the rate 25% each hour. At 12:00 noon the diameter of the puddle was 3.02 meters.
A. Complete the table below.( hint: if 25% evaporates in 1 hour, how much of the puddle remains?)
Hours after 12:00 noon 0 1 2 3
Area of puddle (cm2)
B. Write an equation for the area of the puddle in terms of the number of hours after 12:00 noon.
C. How large is the puddle at midnight?
D. Predict when the puddle is less than 100 square centimeters.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
3.02 m = 302 cm
radius = 151 cm
Area of puddle = pi%2Ar%5E2
pi%2A151%5E2+=+71631cm2
B.A+=+%28.75%5En%29%2A71631cm2 where n is number of hours since noon
C.A+=+%28.75%5E12%29%2A71631cm2
A+=+.0317%2A71631cm2
A+=+2271cm2
D. %28.75%5En%29%2A71631+%3C+100
n%2Alog%28.75%29+%2B+log%2871631%29+%3C+log%28100%29
-.125n+%2B+.145+%2B+5+%3C+2
-.125n+%3C+-2.855
n+%3E+22.84 hrs
Thats about 10:50 AM next day, I think
Maybe I made mistake(s), but that's my method