Can you pleasetelll me if i did this problem correctly? =]?

Question

on a weekend trip, you average 35 mph in the city and 60mph on the highway. if the 150 mile trip took 3 hours how much of the time were you driving in the city? I DID THIS ALREADY AND MY ANSWER WAS 1 HOUR..IS THAT RIGHT??

i did 35+60 =95 so then 150-95=55 then i was like okay if the highway took 60mph and it was 55 left then it would just go to the highway so only 1 hour was spent on the city. RIGHT OR WRONG??

I DIDNT DO THIS ONE...BECAUSE I DONT KNOW HOW..HELP?

and on august 15th 1995 the concorde flew 35,035 miles from new york city to new york city in 31 hours 27 minutes. what was the average speed?

Answer 1

ok, the first one I'm not sure about, but for the second one:

take the total miles and divide by the time it took to find the average speed (mph)

Answer 2

Aw, beginning algebra.   Hang in there.   I spent a month of algebra crying about homework and then suddenly.. BAM!  it made sense.   And then I got the best grades in the class.  Don't give up!!

So, sorry, that's wrong.   You can't add or subtract different units from each other.  Time - miles = ???  See how that doesn't make any sense?  

You probably went over this in class and it's probably in your textbook, so you should look over your textbook again.   But this is the rule that is going to help you the most:

Distance = Speed times Time.

Your total distance in this problem is 150 miles.    The total time is 3 hours.   Part of that time was spent on the city.   We'll call that t.  The time spent on the highway is then (3-t).   You know both speeds.   Multiplying the speed times the time traveled at that speed gives you the distance.  Make sense?   You have two different speeds and two different distances.   Adding together the product of those two will give you the total distance.

SO

150 miles = (35mph)X(t) +  (60mph)(3-t)

Solve for t.  You definitely should have gone over that in class.  

The second problem is ridiculously easy now that you know this:

Distance = Speed times Time

You know the distance and the time, just solve for the speed.  

See, easy!