First, when master and apprentice made 108 sets, they made 108-20-8=80 sets at a speed of 6: 4. Then master made 80*6/ 10=48 sets of 80 sets, and disciples made 32 sets. At this time, Master made 48 sets.

Step 2: When the apprentice makes 100 sets, the apprentice makes 100-40=60 sets and the master makes 60 sets.

Step 3: Master always makes 60+68= 128 sets.