Zhang Cun needs to build a road with a length of 1 200m, and it will take 20 days for a team and 15 days for a team. They each worked for four days, and * * * repaired a fraction of the road.

20/1200 = 60 (daily speed of a)

15/1200 = 80 (daily speed of b)

4 * 60 = 240(4-day journey)

4*80=320 (B 4-day trip)

320+240=560 (total distance)

That is, * * * took a break of 560/120056/1205.6/123.2/16/507/15.

Homework:

Language: 2/5=24/60=24 minutes

Math: 2/9= 13.333/60 = about 14 minutes.

Calligraphy:1115 = 48/60 = 48 minutes.

In other words, calligraphy takes tens of seconds more than homework, 0.666/60 hours.

If you are incompetent or wrong, please give me more advice.