Answer: 1.78 L are needed to complete the gallon and it will take 29.66 min to completely fill it
Step-by-step explanation:
The question in english is:
A gallon of water needs to be filled, in 2 liters it takes 30 minutes. How many liters do I need to complete the gallon and what is the time it takes me to fill it?
We know 1 gallon is equal to 3.78 liters:
[tex]1 gal=3.78 L[/tex]
In addition, we are told you have filled the gallon with [tex]2 L[/tex] at a rate of [tex]\frac{2 L}{30 min}=0.06 L/min[/tex].
So, if we want to know how many liters are left to completely fill the gallon, we have to sbstract the [tex]2 L[/tex] to the total amount of a gallon:
[tex]3.78 L-2 L=1.78 L[/tex] This is the amount you need to complete the gallon
On the other hand, the rate is defined as:
[tex]rate=\frac{Liters}{time}[/tex]
Isolating [tex]time[/tex]:
[tex]time=\frac{Liters}{rate}[/tex]
Then, if we input the [tex]1.78 L[/tex] we need to fill the gallon we will have the time:
[tex]time=\frac{1.78 L}{0.06 L/min}[/tex]
[tex]time=29.66 min[/tex] This is the time you need to fill the gallon