A can complete a piece of work alone in 10 days and B can complete the same piece of work alone in 15 days. Working together, A, B and C can complete this work in 4 \( \frac{1}{2} \) days. If B does not work, while A and C work on alternate days starting with A, then in how many days will the work be completed?
13 \( \frac{1}{9} \)
13 \( \frac{1}{5} \)
13
12 \( \frac{2}{3} \)
In the following table, where would a broken plastic bucket be placed?
| Safely combustible | Not safely combustible | |
| Recyclable | A | B |
| Non-recyclable | C | D |