+20 KB began a 186-mile bicycle trip to build up stamina for a triathlon competition. Unfortunately, the bicycle chain broke, so he finished the trip walking. The whole trip took 6 hrs. If KB walks at a rate of 4 mph and rides at 40 mph, find the amt of time he spent on his bicycle. Thank you for your assistance.
+129899 Here's another way to do this without simultaneous equations.....
Call the time on the bicycle "x".....then the time walking was (6-x)
And....rate times time = distance
So the amount of time on the bike times its rate plus the amount of time walking times that rate = total distance.
40x + 4(6-x) = 186
40x + 24 - 4x = 186 simplify
36x = 162 divide both sides by 36
x = 4 + 1/2 hrs = 4 hrs 30 minutes
And that's the time on the bike
+118687 Let B be the distance ridden and let W be the distance walked.
$$B+W=186 \quad(1)$$
now speed=distance/time
so time = distance/speed
Time for the bike ride = B/40
Time for walking = W/4
$$\frac{B}{40}+\frac{W}{4}=6$$
multiply both sides by 40 and we have
$$B+10W=240\quad (2)$$
solve equations 1 and 2 simultaneously to get your answers. 
+129899 Here's another way to do this without simultaneous equations.....
Call the time on the bicycle "x".....then the time walking was (6-x)
And....rate times time = distance
So the amount of time on the bike times its rate plus the amount of time walking times that rate = total distance.
40x + 4(6-x) = 186
40x + 24 - 4x = 186 simplify
36x = 162 divide both sides by 36
x = 4 + 1/2 hrs = 4 hrs 30 minutes
And that's the time on the bike
