SOLUTION: A family travel 18 miles and returns. It takes 8 hours to make the round trip. their rate in still water is twice the rate of the current. Find the rate of the current.

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A family travel 18 miles and returns. It takes 8 hours to make the round trip. their rate in still water is twice the rate of the current. Find the rate of the current.      Log On


   



Question 876290: A family travel 18 miles and returns. It takes 8 hours to make the round trip. their rate in still water is twice the rate of the current. Find the rate of the current.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 
Hi
average speed = 36%2F8 = 4.5mph
r = 2c where c is the rate of the current
+18%2F%283c%29+%2B+18%2Fc+=+8hr| |Multiplying thru by 3c so as all denominators = 1
18 + 54 = 24c
72/24 = c = 3mph