Answer:
1/2 mph
Step-by-step explanation:
Given :
Distance traveled, D = 12 miles
Upstream Swim time = 4 hours
Return swim time = 3 hours
Upstream rate = 12/4 = 3 mph
Return rate = 12/3 = 4 mph
Let
swim rate = s
Current rate = c
s - c = upstream rate
s + c = return rate
s - c = 3 - - - (1)
s + c = 4 - - -(2)
From (1)
s = 3 + c
Put into (2)
3 + c + c = 4
3 + 2c = 4
2c = 4 - 3
2c = 1
c = 1/2 mph
Hence, rate of current = 0.5mph
