Answer: 60 gallon remained in the tank.
Explanation:
Since, the initial quantity of the liquid in the tank = 64 gallon,
The quantity that is lost = 6 1/4 % of the initial quantity
= 25/4% of 64
=

=

=

= 4 gallon,
Hence, the remaining quantity of the liquid = Initial quantity - Lost quantity
= 64 - 4 = 60 gallon.