After sailing 12 mi, a sailor changed direction and increased the boat's speed by 4 mph. an additional 18 mi was sailed at the i

Question

yan [13]

3 years ago

6

After sailing 12 mi, a sailor changed direction and increased the boat's speed by 4 mph. an additional 18 mi was sailed at the i

ncreased speed. the total sailing time was 3 h. find the rate of the boat for the first 12 mi.

Mathematics

1 answer:

inessss [21] · Answer 1 · 2022-08-13T07:15:56+03:00

inessss [21]3 years ago

8 0

Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr