Sarah starts with 3 fish
in 1 month she will have 6 fish
after 2 months she will have 12
in 3 months she will have 24
Answer:
Step-by-step explanation:
The average scores s (on a 100 point scale) for the students can be modeled by
s = 75 - 6 In(t + 1), 0 < t < 12
where t is the time in months.
a) Since the students were given an exam and then retested monthly with equivalent exams, then,
For the original exam, t = 0
Therefore,
s = 75 - 6 In(0 + 1) = 75 - 6 In1
s = 75 - 6 × 0 = 75
b) the average score after 4 months, t = 4
Therefore,
s = 75 - 6 In(4 + 1) = 75 - 6 In5
s = 75 - 9.66 = 65.34
c) s = 60
Therefore,
60 = 75 - 6 In(t + 1)
6 In(t + 1) = 75 - 60 = 15
In(t + 1) = 15/6 = 2.5
t + 1 = e^2.5 = 12.18
t = 12.18 - 1 = 11.18
t = 11 approximately
Answer:
<em>y=0.10(t)+0.25 </em>
<em>27 minutes and 30 seconds </em>
Step-by-step explanation:
We know that you start with 25 cents as a service fee, this is for making the call. For each minute you talk, 10 cents are added. Multiply the number of minutes spent by 10 cents a minute for the cost based on the call. Then add the 25 cents service fee.
If you talked for 5 minutes:
y=0.10(5)+0.25
y=0.50+0.25
y=0.75
75 Cents
For three dollars, you would plug in 3 for y
3.00=0.10(t)+0.25
-0.25 -0.25
2.75=0.10(t)
divide both sides by 0.10 to get
27.5=t
You can talk for 27 minutes and 30 seconds
27 minutes
<u>Hope this helps :-)</u>
