Kelli swam upstream for some distance in one hour. she then swam downstream for the same distance in only 6 minutes. if the river flows at 5 km/hr, how fast can kelli swim in still water?

6.11 km/hr

Step-by-step explanation:

We will use the distance equation:

Where D is distance (in km), r is the speed/rate (in km/hr), and t is the time taken (in hours)

where c is current rate (river flow rate)

kelli swam upstream for some distance in one hour:

We can write

she then swam downstream for the same distance in only 6 minutes:

* note 6 minutes in hours is hr

We can write

Since the river flows at 5km/hr, c is 5 and total distance is equal, so we can equate the distance and solve for r:

In decimal, 6.11 km/hr. This is Kelli's speed in still water.

people went from manufacturing one object at a time by hand to manufacturing many objects in factories

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step-by-step explanation: