Answer:
The number of pumps and hours) vary inversely.
The constant of variation is 20.
Step-by-step explanation:
Let x be number of pumps and y be number of hours.
We have been given that working together, two identical water pumps can fill a pull in 10 hours. This means while working alone the pumps will take 2 times as much time to fill the tank.
As we increase number of pumps (x), number of hours (y) is decreasing and as we decrease x our y is increasing, therefore, number of pumps (x) and hours (y) vary inversely.
Since we know that an inversely proportion equation is in form: , where, k is constant of variation.
Upon substituting our given values in above equation we will get,
Upon multiplying both sides of our equation by 2 we will get,
Therefore, the constant of variation is 20.