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:

In addition, we are told you have filled the gallon with
at a rate of
.
So, if we want to know how many liters are left to completely fill the gallon, we have to sbstract the
to the total amount of a gallon:
This is the amount you need to complete the gallon
On the other hand, the rate is defined as:

Isolating
:

Then, if we input the
we need to fill the gallon we will have the time:

This is the time you need to fill the gallon