Answer: 3 times.
Step-by-step explanation:
Here, The Volume of the gas tank = 4710 
While, The radius of the cylindrical shaped bucket = 5 in
And, Height of the cylindrical shaped bucket = 20 in
Therefore, The volume of the bucket = 
= 3.14 × 5 × 5 × 20 = 1570
According to the question, cylinder shaped bucket is used to fill the tank.
Thus, The number of times the bucket will be used to fill the tank
= The Volume of the gas tank/ The volume of the bucket = 4710/1570 = 3
Therefore, The bucket will be used three times to fill the tank.