Answer is 12 1/2 buckets to fill the bath
( or 12.5 buckets)
Step by step
We know the bath holds 100 quarts
We know 100 quarts is equal to 25 gallons
( 4qts to 1 gallon)
If Abby is using a 2 gallon bucket, divide 25 gallons by 2
25/2 = 12 1/2 buckets to fill the bath