Question 14579: two cares leave st.louis. one travels north and one travles south. the care traveling north is moving 10mph faster than the care traveling south. after three hours the cars are 354 miles apart. how fast is each car traveling?
Found 2 solutions by glabow, dolphingurl:
Answer by glabow(165)   (Show Source):
You can put this solution on YOUR website! Ah, if I could get rid of my cares so easily! [watch those typos]
It really doesn't matter if they are going North, South, or any other direction. The question boils down to: two cars travel. One goes at a speed of ? miles per hour. Let's use the letter x for that unknown speed. The other one goes x+10 miles per hour. [Do you see why?] After three hours of travel, the total distance they have traveled is 354 miles.
The slower car goes 3 hours times x miles per hour, which is 3x miles.
The faster car goes 3 hours times x+10 miles per hour, which is 3(x+10) miles.
The total distance they travel is 3x + 3(x+10) = 354 miles.
This is easy to solve.
3x + 3x + 30 = 354 [simplifying the expression]
6x + 30 = 354 [more simplifying]
6x = 324 [subtracting 30 from both sides]
x = 54 [dividing both sides by 6]
x+10 = 64
Checking: 3(54) + 3(64) = 162 + 192 = 354
Answer by dolphingurl(4) (Show Source):
You can put this solution on YOUR website! It really doesn't matter if they are going North, South, or any other direction. The question boils down to: two cars travel. One goes at a speed of how many miles per hour. Let's use the letter x for that unknown speed. The other one goes x+10 miles per hour. Do you see why? After three hours of travel, the total distance they have traveled is 354 miles.
The slower car goes 3 hours times x miles per hour, which is 3x miles.
The faster car goes 3 hours times x+10 miles per hour, which is 3(x+10) miles.
The total distance they travel is 3x + 3(x+10) = 354 miles.
This is easy to solve.
3x + 3x + 30 = 254 [simplifying the expression]
6x + 30 = 354 [more simplifying]
6x = 324 [subtracting 30 from both sides]
x = 54 [dividing both sides by 6]
x+10 = 64
Checking: 3(54) + 3(64) = 162 + 192 = 354
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