The task is to generate the correct answer for a given math problem.

Q: Problem: the average salary of 20 people in the shipping department at a certain firm is $ 1000 . the salary of 10 of the employees is $ 600 each and the salary of 6 of the employees is $ 200 each . what is the average salary of the remaining employees ?

A: $ 3200
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Q: Problem: pipe a can fill a tank in 6 hours . due to a leak at the bottom , it takes 10 hours for the pipe a to fill the tank . in what time can the leak alone empty the full tank ?

A: 15
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Q: Problem: . a car covers a distance of 810 km in 5 hours . find its speed ?

A:
162
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