In a shooting match, eight clay targets are arranged in two hanging columns of three targets each and one column of two targets. A marksman is to break all the targets according to the following rules: 

1) The marksman first chooses a column from which a target is to be broken. 
2) The marksman must then break the lowest remaining target in the chosen column. 

If the rules are followed, in how many different orders can the eight targets be broken?
1. **Define the problem in terms of sequences:**
   - Let $X$ represent shooting a target from the first column.
   - Let $Y$ represent shooting a target from the second column.
   - Let $Z$ represent shooting a target from the third column.

2. **Understand the constraints:**
   - Each column has a fixed number of targets: 3 in the first column, 3 in the second column, and 2 in the third column.
   - The order of shooting within each column is fixed: the lowest remaining target must be shot first.

3. **Formulate the problem as a permutation:**
   - We need to find the number of ways to arrange the sequence of shots represented by the string $XXXYYYZZ$.

4. **Calculate the number of permutations:**
   - The number of ways to arrange the letters in the string $XXXYYYZZ$ is given by the multinomial coefficient:
     \[
     \binom{8}{3,3,2} = \frac{8!}{3!3!2!}
     \]
   - Calculate the factorials:
     \[
     8! = 40320, \quad 3! = 6, \quad 2! = 2
     \]
   - Substitute these values into the multinomial coefficient formula:
     \[
     \binom{8}{3,3,2} = \frac{40320}{3! \cdot 3! \cdot 2!} = \frac{40320}{6 \cdot 6 \cdot 2} = \frac{40320}{72} = 560
     \]

Conclusion:
\[
\boxed{560}
\]