2. A kayaker travels 4 miles upstream and 4 miles downstream in a total of 6 hours. In still
water, the kayaker can travel at an average speed of 2.3 mi/h.
Determine the average speed of the river's current.

The average speed of the river's current is 1.49107 miles per hour

Solution:

Given that,

Upstream distance = 4 miles

Downstream distance = 4 miles

If the speed of a boat in still water is u km\hr and the speed of the stream is v km/hr then:

Speed downstream = u + v km\hr

Speed upstream = u - v km\hr

From given,

Speed in still water = 2.3 miles per hour

u = 2.3

Therefore,

speed downstream = 2.3 + v

Speed upstream = 2.3 - v

The total time is 6 hours

Therefore,

Thus we get,

Thus the average speed of the river's current is 1.49107 miles per hour

answer: 21$

step-by-step explanation:

$42 / $14 = 3   (ratio 3: 1)

$7 x 3 = $21

just do 5.2 + 2 ( 7.2) and 1/3 x 3 (.9) and youv'e got your equation. 0.9( 9/10) + 7.2 ^2 = 16.4 hope i could !

step-by-step explanation: