Question 987202
My kids’ bathtub is being drained. Since it is an ordinary tub, it can be modeled by the function 
V(t) = -15t + 45 where V(t) is the volume of the tub in gallons and t is the time that has passed in minutes.
Note: Your volume equation implies the capacity of the tub is 45  

1.Based on the function V(t) = -15t + 45, when will the tub be half full?
22.5 = -15t + 45
-22.5 = -15t
time = 1.5 minutes
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2.What is the practical domain in this problem? Use appropriate notation in your answer.
Solve::
0 = -15t + 45
t = 3 minutes
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Domain:: 0<= t <=3
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3.What is the practical range? Use the appropriate notation in your answer.
0<= V(t) <= 45
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4.My tub is a garden tub. When I drain it I can model the volume of water in it by v(T) = -20T + 50 where v(T) is the volume of the tub in gallons and T is the time that has passed in minutes. Given all this, which tub drains faster, my kids’ tub, or mine? Explain your reasoning.
Solve:
0 = -20T + 50
T = 50/20
T = 2.5 minutes
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Ans: Your tub has 50 gallons and empties in 2.5 minutes.
Your's drains faster.
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Cheers,
Stan H.
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