5-A15
Wind/Current Word Problems
Math 8H
with Review
ALL WORK IS TO BE SHOWN NEATLY in your composition book. Label your variables, write a
system of equations, solve the system using either substitution or linear combinations, then answer
the problem. Remember word problems need word answers.
1.
A plane goes 2000 miles in five hours flying against the wind. The same plane takes four hours
to fly the same distance with the wind. What’s the rate of the plane in still air, and the rate
of the air current?
2.
A man took three hours to go 24 miles downstream, and six hours to return the 24 miles
upstream. What was the rate of the boat in still water and the rate of the current?
3.
Flying with the wind, Wonder Woman flew her aircraft 300 miles in five hours. To return the
300 miles, she took six hours, flying against the wind. What was the rate of the superplane in
still air and the rate of the air current?
4.
A woman took three hours to go 48 miles downstream, and six hours to return upstream all 48
miles. What was the rate of the boat in still water and the rate of the current?
5.
A small plane can fly 2400 km in 10 hours flying into the wind. With the wind behind it, the
plane can fly 3200 km in the same time. What is the speed of the wind?
6.
Alice cycles to Carla’s house at 12 mph and returns by car at 36 mph. If the round trip takes
1 hour, how far from Carla does Alice live?
7.
Pat biked 1 mile in 3 minutes with the wind at her back, and then she returned in 4 minutes
riding against the wind. What was the speed of the wind in miles per hour?
8.
Meg is 20 years younger than Phillip. In three years Phillip will be twice as old as Meg will be.
How is each now?
9.
Flying against the wind, Mr. Trump’s company plane flew 450 miles from one airport to
another in 1½ hours. The return trip, with no change in the wind’s speed or direction, took 1 ¼
hours. What was the speed of the wind?
10.
Two cars pass Exit 20 on the turnpike at 8:00 A.M. One car is traveling north and the other
is traveling south at a speed that is 4 km/h faster than the northbound car. At 8:45 A.M. the
cars are 117 km apart. Find the speed of the southbound car.
Key 5 – A15
1.
2.
3.
4.
5.
6.
with
4(p + w) = 2000
against
5(p – w) = 2000
Plane 450 mph,
Wind 50 mph.
with
3(b + c) = 24
against
6(b – c) = 24
Boat 6 mph,
Current 2 mph.
with
5(p + w) = 300
against
6(p – w) = 300
Plane 55 mph,
Wind 5 mph.
with
3(b + c) = 48
against
6(b – c) = 48
Boat 12 mph,
Current 4 mph.
with
10(p + w) = 3200
against
10(p – w) = 2400
Plane 280 kmh,
Wind 40 kmh.
Let t = time there
Let r = time returning
t + r = 1
12t = 36r
3
4
t = ,
r =
1
4
therefore…
They live 9 miles apart.
7.
with
against
3
(b + w) = 1
60
4
(b – w) = 1
60
The wind was 2½ mph.
8.
Let m = Meg’s age now
Let p = Phillip’s age now
p – 20 = m
p + 3 = 2(m + 3)
Phillip is 37, and Meg is 17
years old.
9.
with
against
5
(p + w) = 450
4
3
(p – w) = 450
2
The wind was 30 mph.
10. Let x = rate of SB car
Let y = rate of NB car
x – 4 = y
3
3
x + y = 117
4
4
The southbound car is going
80 kmh.