Friday

September 19, 2014

September 19, 2014

Posted by **Lori** on Wednesday, August 1, 2012 at 6:32pm.

- math -
**MathMate**, Wednesday, August 1, 2012 at 6:45pmSet-up:

Let v=speed of boat

c=speed of current

Distance = speed*time

Upstream:

120=(v-c)*20 ...(1)

Downstream:

120=(v+c)*10 ...(2)

Solve for v and c.

- math -
**Lori**, Wednesday, August 1, 2012 at 7:03pmOkay, I got:

v+6-c and c=c-6 for 120=(v-c)*20

AND:

c=12-v and v=6/5-c for 120=(v+c)*10

Now what do I do?

- math -
**MathMate**, Wednesday, August 1, 2012 at 7:13pmWhat you really want to do is to reduce the variables in simpler terms by dividing both sides by 20:

v-c=120/20=6 ...(1a)

v+c=120/10=12...(1b)

This is a sum and difference form where the solution can be done mentally:

v=(sum+difference)/2=9

c=(sum-difference)/2=3

**Answer this Question**

**Related Questions**

algebra - tugboat goes 160 miles upstream in 10 hours. The return trip ...

MAT 116 - A tugboat goes 180 miles upstream in 10 hours. The return trip ...

alegbra - a tugboat goes 160 miles upstream in 20 hours. The return trip ...

algebra - A tugboat goes 180 miles upstream in 15 hours. The return trip ...

algebra - a tugboat goes 160 miles upstream in 20 hours. The return trip ...

Algebra - A tugboat goes 160 miles up stream in 20 hours, return trip downstream...

algerbia - a tugboat goes 120 miles up streem in 15 hours it takes 10 hours to ...

math - A tugboat can go 10 miles upstream in the same time as it can go 15 miles...

alegrbra - A tugboat is going 100 miles upstream in 10 hours and returning ...

physics - a crew member is walking on a tugboat that is pulling a barge. the ...