To make a batch of parts, the efficiency ratio of Party A and Party B is 3: 4, and it takes 16 days for Party A to complete this batch of parts alone, so how many days does it take for two people to cooperate?

Efficiency of a:116,

Each serving: (116)/3 =1/48.

Efficiency of b: (1/48) x4 =112.

* * * Requirements for cooperation between two people:1(112+116) = 48/7 (days).

The hound found a running rabbit in front of it at 10 meter, and immediately caught up with it. The hound took a big step. It runs five steps, and the rabbit runs nine steps, but the rabbit is fast. The hound runs two steps, but the rabbit can run three. How many meters can a hound run to catch up with a rabbit?

Speed ratio: hound: hare =9x2:5x3= 18: 15.

Every time the hound runs 18m, it catches up with the hare 18- 15 = 3m.

To catch up with 10 meter, you need to run: (10/3)x 18=60 (meters).