Answer:
oki wsp
Step-by-step explanation:
Speed = Distance / Time
Distance = Speed*Time
For this problem, we should bear in mind that current speed has an impact on the boat speed...
for upstream, the boat goes against the current, and so its speed is
U = V - C
where V is the speed of the boat
C is the current speed
for downstream, it will be:
D = V + C
Convert the problem into mathematical equations:
4D + 3U = 116
3D + 4U = 108
4(V+C) + 3(V-C) = 116
4V + 4C + 3V -3C =116
7V + C = 116
3(V+C) + 4(V-C) = 108
3V + 3C + 4V - 4C = 108
7V - C = 108
Solving the equations:
7V + C = 116
7V - C = 108
14V = 224
V = 16km/hr —-> speed of boat
to get C:
7(16) + C = 116
C = 4km/hr
We can set up a proportion to find this
60 x
--- = ----
100 1200
then we cross multiply and divide to solve
60 times 1200 is 72000 divided by 100 is 720
now we know his employer pays 720 out of 1200
we subtract to find out how much he pays
1200-720 is 480
fred pays 480
18 miles
183.6 divided by 10.2 = 18, and to check the answer if we multiply 18 and 10.2 it equals 183.6
X=5 is your answer to this
