Answer:
Each bucket will be
full
Explanation:
First add up all the different fractions to find out how many buckets of water are in all 3 buckets combined.
Adding up the fractions we get the expression:

To add these fractions first find the LCM(least common multiple of the denominators, 12, 4 and 3
This is the smallest number divisible by all 3 numbers without a remainder
There are several strategies for finding the LCM but here we can see that 12 is evenly divisible by12, 4 and 3
We convert each of the fractions to have the same denominator as the LCM of 12 and adjust the numerator accordingly
Multiply each of the fractions by the LCM
12 x 5/12 = 5
12 x 3/4 = 9
12 x 1/3 = 4
These will become the numerators in the addition with the common denominator of 12

This is how many buckets it will take to hold the water from all three buckets
Divide numerator and denominator by 6 to reduce to lowest fraction

This is 1 1/2 buckets. If this amount of water is to be evenly divided among 3 buckets then the amount of water in each bucket

So each bucket will be half full