Problema Solution
A cruise boat travels 24 miles downstream in 2 hours and returns upstream in 12 hours. Find the rate of the stream
Answer provided by our tutors
-----------------------
Down stream DATA:
distance =24 miles ; time =2 hrs: rate = d/t = 24/2 =12 mph
---------------------------
Up stream DATA:
distance = 24 miles ; time = 12hrs. rate = 24/12 = 2 mph
------------------------
Equations
Down stream rate: b + c = 12 mph
Upstream rate...: b - c =2
-------------------------------------
Add to get 2b = 14
b = 7 mph (rate of the boat in still water)
---
Substitute to find "c":
b+c = 7 + c =12
c = 12-7 = 5 mph (speed of the current)