Each tractor is equipped with 1 piece of cultivated land every day.

Two sets of 10 can culture 2× 10=20 copies per day.

Five units can cultivate 5×8=40 strands in 8 days.

40-20=20 portions,

It was the original tractor in 10-8=2 days.

20/2= 10 copies can be cultured every day.

So there are 10 tractors.

2.

Let each pump pump 1 serving per hour.

Five units can draw 5×20= 100 copies in 20 hours.

Eight sets 15 hours can draw 8× 15= 120 copies.

The difference is 120- 100=20 copies, that is, the water leaked from the water outlet within 20- 15=5 hours.

Water leakage per hour 20/5=4 copies.

There used to be 100+4×20= 180 parts of water.

It takes 180/4=45 hours to complete the leakage.