Answer
The fraction of the tank filled with gas at the end second day is \[\frac{5}{12}\].
Work Step by Step
Assume the capacity of the tank be a least common multiple of \[3\]and \[4\] that is \[12\] liters.
The first day \[{{\frac{1}{4}}^{th}}\] of the tank was used that is \[\frac{12}{4}=3\]liters used.
The second day \[{{\frac{1}{3}}^{rd}}\] of the tank was used that is \[\frac{12}{3}=4\]liters used.
So, total consumed quantity is \[3+4=7\]liters.
Therefore, quantity left in the tank is\[12-7=5\]liters.
Hence, The fraction of the tank filled with gas at the end second day is \[\frac{5}{12}\].
