SOLUTION: Keiko bicycles 4 km/h faster than javier. In the same time it takes Javier to bicycle 30 km, Keiki can bicycle 42 jm. How fast does each bicyclist travel? javier travel ? Kei

Algebra ->  Proportions  -> Lessons -> SOLUTION: Keiko bicycles 4 km/h faster than javier. In the same time it takes Javier to bicycle 30 km, Keiki can bicycle 42 jm. How fast does each bicyclist travel? javier travel ? Kei      Log On


   

Question 200410: Keiko bicycles 4 km/h faster than javier. In the same time it takes Javier to bicycle 30 km, Keiki can bicycle 42 jm. How fast does each bicyclist travel?
javier travel ?
Keiko travels ?
Found 2 solutions by ankor@dixie-net.com, RAY100:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Keiko bicycles 4 km/h faster than javier.
In the same time it takes Javier to bicycle 30 km, Keiki can bicycle 42 km.
How fast does each bicyclist travel?
;
Let s = j's speed
then
(s+4) = k's speed
:
Write a time equation, Time = dist%2Fspeed
:
k's time = j's time
42%2F%28%28s%2B4%29%29 = 30%2Fs
Cross multiply
42s = 30(s+4)
42s = 30s + 120
42x - 30s = 120
12s = 120
s = 120%2F12
s = 10 km/hr is j's speed
and
10 + 4 = 14 km/hr is k' speed
:
;
Check solution by finding the times:
42/14 = 3 hrs
30/10 = 3 hrs, confirms our solutions

Answer by RAY100(1637) About Me  (Show Source):
You can put this solution on YOUR website!
Let K = velocity of Keiko,,,,,,,Let J = velocity of Javier ( km/hr),,,,Let t = time (hrs)
.
K= J + 4
.
J=30 /t,,,,,,,K=42/t
.
42/t = 30/t +4,,,,,,,,,, (substitute into (1) )
.
42 = 30 +4t,,,,,,,,,,,,,,,( multiply thru by t)
.
12 = 4t
.
t = 3 hrs
.
J=30 /3 =10 km / hr,,,,,,,,,K=42 /3 =14 km/hr,,,,,ANSWER
.
checking in (1) 14 = 10 +4,,,,,ok