Ughhh help me pleaseee!?

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? help me..i have like six problems like this and i just need an example done first soo please helpp. =]

Answer 1

alright so your trying to add in 35 mph and 60 mph multiple times to try to fit it to be the the right number so i'll help. You would only be driving on the highway twice

60+60

then you add the 35mph

60+60+35 and you get 155. Which is a little over but I'm sure it might work but Im not sure.

Then you were only driving in the city for one hour. or about 52.5 hours but I'm not completely sure. I hope I helped.

Answer 2

c = time driving in the city

h = time driving on the highway

distance = speed x time

35c + 60h = 150 (distance in city + distance on highway = total distance)

c+h = 3 (time in city + time on highway = total time)

so h = 3-c

Substituting this into the first equation gives:

35c + 60(3-c) = 150

35c + 180 - 60c = 150

30 = 25c

c = 30/ 25 hours = 1.2 hours = 1800/25 minutes = 72 minutes

You would drive for one hour and 12 minutes in the city.