SOLUTION: hey, would you please be able to help me with the following question a student runs three times as fast as she walks. she walked for 3 hours and ran for 2 hours and altogether wen

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: hey, would you please be able to help me with the following question a student runs three times as fast as she walks. she walked for 3 hours and ran for 2 hours and altogether wen      Log On


   

Question 571510: hey, would you please be able to help me with the following question
a student runs three times as fast as she walks. she walked for 3 hours and ran for 2 hours and altogether went 36km. what was her speed of walking
thanks
Found 2 solutions by josmiceli, reviewermath:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +s+ = her speed walking in km/hr
+3s+ = her speed running in km/hr
Let +d+ = distance traveled walking in km
+36+-+d+ = distance traveled running in km
-----------------
Her equation walking:
(1) +d+=+s%2A3+
Her equation running:
(2) +36+-+d+=+3s%2A2+
--------------------
(2) +36+-+d+=+6s+
Substitute (1) into (2)
(2) 36+-+3s+=+6s+
(2) +9s+=+36+
(2) +s+=+4+
Her speed walking was 4 km/hr
check answer:
(1) +d+=+s%2A3+
(1) +d+=+4%2A3+
(1) +d+=+12+
and
(2) +36+-+d+=+3%2A4%2A2+
(2) +36+-+d+=+24+
(2) +d+=+12+
OK

Answer by reviewermath(1029) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = walking speed
so 3x = running seed
Use distance+=+speed%2Atime
Equation: 3x + 2(3x) = 36
9x = 36
x = 4
speed of walking = 4kph
Answer: 4 kph