5. The apprentice makes 24 parts per hour, and the ratio of parts produced by the master and the apprentice is 3:2, and the master makes 36 parts per hour.

It takes 10 hours for the master to do it alone, and there are 36* 10=360 parts in this batch.

6. Let the original first bundle of wires be x meters long and the original second bundle of wires be (4/7)x meters long.

x- 18=(4/7)x-6

(3/7)x= 12

x=28

It turns out that the first bundle of wires is 28 meters long.