how much longer than train did bus take to make trip?

msjojogirl

New member
Joined
Sep 12, 2008
Messages
3
I'm just not getting this one,

A train traveled m miles at a speed of s mph. A bus following the same route traveled 5 mph slower. How much longer did the bus take than the train to make this trip? Write the answer as a single rational

can someone please help me :D
 
Re: algebra

msjojogirl said:
I'm just not getting this one,

A train traveled m miles at a speed of s mph. A bus following the same route traveled 5 mph slower. How much longer did the bus take than the train to make this trip? Write the answer as a single rational
can someone please help me :D

The equation to use:

time = distance/speed

A train traveled m miles at a speed of s mph.

How long did it take for the train to travel the distance?..............................(1)

A bus following the same route traveled 5 mph slower

What is the speed of the bus?

How long did it take for the bus to travel the distance?..............................(2)

Now subtract (2) from (1) to get the difference in time.
 
Re: algebra

hi again ,
how would you write this in a formula this whole thing is getting to me big time and im to old for this can you help please Terri thanks
 
A roadblock ...

msjojogirl said:
how would you write this in a formula[?] ...

Hello Terri:

I hope you understand that the words "time", "distance", and "speed" each represent numbers in the formula. If you're not sure what I mean, then tell us.

We do not know what these numbers are because this particular exercise does not provide any numbers. However, they do give us symbols for both the distance and the speed.

What is the distance in this problem?

The distance is the number of miles traveled.

The problem gives us a symbol that stands for this number of miles.

m

From now on, if we need to write down the distance when using formulas during the course of solving this exercise, we no longer need to write the word "distance". We can write the symbol m, instead.

You need to start a new line on your piece of paper and write the formula again, except THIS TIME you will not write the word "distance". You will write the symbol m in its place.

Do not write the word "speed", either!

Write the symbol s, instead.

The symbol s stands for the speed of the train. Remember?

So, now, you should have something written on your paper that looks like the following.

\(\displaystyle \mbox{Time} \;=\; \frac{m}{s}\)

I want to make sure at this point that you understand "m/s" is a number. It's a fraction, of course. But a fraction has a single value, so this symbol that looks like a fraction ("m/s") represents a single value. Like I mentioned earlier, we don't know what this number's actual numerical value is yet. In fact, we never will.

If your instructor told me that the train was traveling at 35 miles per hour, and that the distance traveled is 70 miles, then that would be a different story. If we're told that m stands for 70 and s stands for 35, then it's obvious that Time = 2 hours.

Oh, by the way, do you realize that we will not be reporting a number of hours? Do you understand that the answer to your exercise is not a number? (The instruction given at the very end of the exercise gives us a hint at what the answer will look like.)

The answer to your exercise is an algebraic expression using the symbols m and s. This expression represents the amount of extra time it took the bus over the train. But, I'm getting ahead of myself. We've only finished the first of three steps, so far.

Okay. Now I would like you to answer the following two questions before continuing on to the next step in solving your exercise.

1) What does the symbol m/s stand for? In other words, if I tell you (for example) that m/s = 3, then please tell me specifically what this number means in your exercise. (Stuck again? Look at what you wrote on the paper and think about what we know about the symbol s.)

2) Start a new line on your piece of paper and write the formula yet again, only this time do it for the bus. In other words, show me what the expression looks like that stands for the time that it took the bus.

OR, if things seem clear to you now, then go ahead and subtract the train time from the bus time, and simplify the resulting expression into a single rational expression.

Cheers,

~ Mark :)
 
Top