PLEASE HELP ME.. WILL FAN AND GIVE MEDAL

Question

kmullis6 · Answer

A student is running a 5-kilometer race. He runs 1 kilometer every 3 minutes. Select the function that describes his distance from the finish line.

f(x) = - 1 over 3x + 5

f(x) = - 1 over 5x + 3

f(x) = 1 over 5x + 5

f(x) = 1 over 3x + 3

anteater · Answer

His distance from the finish line should be 5 minus however far he has run, which will depend on the number of minutes, x, he has been running. Since he runs 1 km every 3 minutes, that would mean he would run 1/3 km per minute. So, the distance he runs in x minutes would be x/3. So, 5 - x/3 should be the answer, but that is not one of the choices given, which means we need to figure out which one of the answers given is equivalent to 5 - x/3.

anteater · Answer

I hate to tell you this, but I think there is a problem with your problem!

anteater · Answer

Let me explain.

kmullis6 · Answer

Haha ok

anteater · Answer

If he is at the finish line, what is his distance from the finish line?

anteater · Answer

I'm not kidding. :)  I think this problem was improperly crafted.

anteater · Answer

Would you agree that if he is at the finish line, then his distance from the finish line is 0?

kmullis6 · Answer

Yes.

anteater · Answer

Ok, now look at all of the possible choices they have given you. They all involve fractions:  -1/(3x+5); -1/(5x+3); 1/(5x+5); 1/(3x+3)

If you think about it, will any of those ever equal 0?

anteater · Answer

They can't, so there is no way to show that the student is at the finish line. The problem itself isn't flawed, but the choices you were given won't work.

kmullis6 · Answer

Ok.

anteater · Answer

I believe that they probably intended for the first choice to be the "correct" response

anteater · Answer

Because if you had this:  -(1/3)x  +  5   that would work.

kmullis6 · Answer

That's what I was thinking. But like you said, the way the question was given just didn't make much sense to me.

anteater · Answer

You are correct. :)

kmullis6 · Answer

Thank you so much for the help. (:

anteater · Answer

You're welcome! FWIW, I promise you can trust me on this!

kmullis6 · Answer

I hope so lol. :P Can you help me with another?

anteater · Answer

I also think that if you are doing a multiple choice online quiz that they probably "meant" for the first choice to be correct.

anteater · Answer

Certainly!

kmullis6 · Answer

Ok I'll make a new question and tag you.

anteater · Answer

Ok :)