# algebra problem : figuring out the speed of boat and water

• Jan 30th 2011, 09:53 PM
avantgardejazz
algebra problem : figuring out the speed of boat and water
I have the algebra problem:

If a boat goes downstream 72 miles in 3 hours and upstream 60 miles in 6 hours, the rate of
the river and the rate of the boat in still water respectively are ________?
a. 7 &16 mph
b. 7&17
c. 6 &17 mph
d. 6 &18
e. none

I know the forumla is r x t = d however i come up with 26 & 10
am i approaching this incorrectly?
• Jan 30th 2011, 11:10 PM
if u is the velocity of the boat and v is the velocity of the river,

(U+V)*3=72
(U-V)*6=60
• Jan 31st 2011, 12:11 AM
BobBali
Yes, the formula for finding out speed (rate) > [tex]Distance (miles)/Time (hours) = Speed (miles/Hr)[math/]

However, in your question it says to find the respective rates of the river in stillwater. Also, it does not make sense when it talks about the rate of the river going upstream, water always flows downstream and in stillwater there will be no flow/speed/rate. The boat will be stationary. Answer, is e.
• Jan 31st 2011, 06:12 AM
bjhopper
Hi BobBali,
Thr question asks for the rate of the river and the rate of the boat in still water.Respectively refers to the order of the answers

bjh