Toni rows a boat 4.5km/h upstream and then turns around and rows 5.5km/h back to her starting point. If her total rowing time is 48 min , for how long does she row upstream?

the distances are hew same, though unknown.

let the distance be d. time = distance/speed. Add up the times:

d/4.5 + d/5.5 = .8

10d = 19.8
d = 1.98km

d/4.5 = .44hour
d/5.5 = .36hour
total = .80 hour = 48 min.

Distance= rate*time

Distance upstream = distance downstream
Time should be converted to hour b/c the units for rate is in /hour. We know the total time so assign one of the times x (upstream time b/c you would only have to solve for x to get its time) and the other the total time in hour-x.

To find out how long Toni rows upstream, we can set up an equation based on the given information.

Let's assume that the time Toni rows upstream is "t" hours.

The time she rows downstream (back to her starting point) would then be (48/60 - t) hours. We convert 48 minutes to hours by dividing it by 60.

Now, we can use the formula: Distance = Speed × Time.

When Toni rows upstream, the distance she covers is 4.5 km/h × t.

When Toni rows downstream, the distance she covers is 5.5 km/h × (48/60 - t).

Since the distance going upstream is the same as the distance going downstream (as she returns to her starting point), we can set up an equation:

4.5t = 5.5 (48/60 - t).

Now, let's solve for t:

4.5t = 5.5 (8/10 - t)
4.5t = 5.5 (4/5 - t)
4.5t = 22/5 - 5.5t
4.5t + 5.5t = 22/5
10t = 22/5
t = (22/5) / 10
t = (22/5) × (1/10)
t = 22/50
t = 0.44

Therefore, Toni rows upstream for approximately 0.44 hours, which is equivalent to 26.4 minutes.