A raft was sent away from point A downstream. A patrol-boat left A 5 hour and 20 min later and caught up with the raft 20 km away from point A. What was the speed of the raft if the speed of the patrol-boat was 12 km/hour?

You have to do something with the 20 minutes.
1 hour = 60 minutes
x hour = 20 minutes Cross multiply.

60 minutes * x = 20 hour minutes
x = 20 hour minutes / 60 minutes
x = 0.33333 hours.

The time = 5.333 later
d = 20 km
r = 12 km/ hour
t = ???

t = d/r = 20/12 = 1.66667 hours.

So the raft set out and has been out for 5.33333 hours + 1.66667 hours.
Total time = 7 hours.
t = 7 hours.
d = 20 km
r = ??
r = d/t
r = 20 km / 7 hours = 2 6/7 km/hour

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bhoopendrasisodiya34 bhoopendrasisodiya34 · Answer 2 · 2022-03-07T12:55:51+01:00

The speed of the raft if the speed of the patrol-boat was 12 km/hour, and it caught the raft in 5 hours 20 min later is 2.857 km/hours.

What is the speed of a body?

The speed of a body is the rate at which it covers the total distance is in the time taken. The speed of the body is given as,

[tex]s=\dfrac{d}{t}[/tex]

Here, (d) is the distance travelled by the body and (t) is time taken by the body to cover that distance.

A raft was sent away from point A downstream. A patrol-boat left A 5 hour and 20 min later and caught up with the raft 20 km away from point A.

Total time the patrol boat took in hours is,

[tex]t=5+\dfrac{20}{60}\\t=5+0.3333\\t=5.3333\rm hrs[/tex]

The speed of the patrol boat is 12 km/hour, and it caught up with the raft 20 km away from point A. Thus, the time taken with this speed to cover 20 km distance is,

[tex]t=\dfrac{20}{12}\\t=\dfrac{}{}1.6667\rm hrs[/tex]

Thus, the total time is,

[tex]t=5.3333+1.6667\\t=7\rm hrs[/tex]

Now as the raft travel 20 km in 7 hours. Therefore, find the speed of raft by putting the values in above formula as,

[tex]s=\dfrac{20}{7}\\s=2.857\rm km/hrs[/tex]

Hence, the speed of the raft if the speed of the patrol-boat was 12 km/hour, and it caught the raft in 5 hours 20 min later is 2.857 km/hours.

Learn more about the speed here:

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