Raj's bathtub is clogged and is draining at a rate of 1.5 gallons of water per minute. The table shows that the amount of water remaining in the bathtub, [tex]y[/tex], is a function of the time in minutes, [tex]x[/tex], that it has been draining.

What is the range of this function?

A. all real numbers such that [tex]y \leq 40[/tex]

B. all real numbers such that [tex]y \geq 0[/tex]

C. all real numbers such that [tex]0 \leq y \leq 40[/tex]

D. all real numbers such that [tex]37.75 \leq y \leq 4[/tex]



Answer :

Let's analyze the situation step by step.

1. Initial Condition:
- The initial amount of water in the bathtub is 40 gallons.

2. Draining Rate:
- Water is draining at a rate of 1.5 gallons per minute.

3. Function of Water Remaining:
- As the water drains, the amount of water remaining in the bathtub can be calculated. For every minute [tex]\( x \)[/tex], the water decreases by [tex]\( 1.5 \times x \)[/tex].
- Therefore, the amount of water [tex]\( y \)[/tex] remaining in the bathtub after [tex]\( x \)[/tex] minutes can be expressed as:
[tex]\[ y = 40 - 1.5x \][/tex]

4. Range of Values for [tex]\( y \)[/tex]:
- To find the range of [tex]\( y \)[/tex], let's determine the possible values that [tex]\( y \)[/tex] can take.
- Initially, when [tex]\( x = 0 \)[/tex]:
[tex]\[ y = 40 - 1.5 \times 0 = 40 \text{ gallons} \][/tex]
- As time progresses, the water keeps draining until the bathtub is empty. The bathtub is empty when all 40 gallons have been drained:
[tex]\[ 40 - 1.5x = 0 \][/tex]
- Solving for [tex]\( x \)[/tex]:
[tex]\[ 1.5x = 40 \implies x = \frac{40}{1.5} = 26.\overline{6} \text{ minutes} \][/tex]
- After [tex]\( 26.\overline{6} \)[/tex] minutes, the water amount [tex]\( y \)[/tex] reaches 0:
[tex]\[ y = 0 \text{ gallons} \][/tex]

5. Identifying the Range:
- The value of [tex]\( y \)[/tex] starts from 40 gallons and decreases to 0 gallons. Therefore, the possible values for [tex]\( y \)[/tex] lie between 0 and 40 gallons inclusive.

Thus, the range of this function is:
[tex]\[ \boxed{\text{all real numbers such that } 0 \leq y \leq 40} \][/tex]