Question 1185133
<br>
Upstream speed: 60/5 = 12km/h
Downstream speed: 60/3 = 20km/h<br>
To solve using formal algebra....<br>
b = boat speed
c = current speed
b+c=20
b-c=12<br>
Solve the system of equations using very basic algebra....<br>
For a less formal solution, you can reason this way:
The 20km/h is the current speed ADDED TO the boat speed; the 12km/h is the current speed SUBTRACTED FROM the boat speed.
That means the boat speed is halfway between 12km/h and 20km/h, which is 16km/h.
And then the current speed is the difference between 16km/h and either 12km/h or 20km/h, which is 4km/h.<br>
ANSWERS:
Boat speed 16km/h
Current speed 4km/h<br>