Question 778218
Method___________speed_________time____________distance
walk_____________4_____________(___)___________(___)
jog______________7_____________(___)___________(___)
TOTAL__________________________2________________11.6


rate*time=distance
Speed*hours=miles
Speed is in unit miles per hour


We need unknown variables, two of them. EITHER choose times OR choose distance.  You form the expression for the other unknown quantities.  

When the question is, "how long did she j and how long did she walk?", which quantity is asked is not clear, but we can answer for both of them.  We will have two sums to use: one sum for time and the other sum for distance.  We will use two equations in two unknowns.


ASSIGN VARIABLES TO TIME

Let w = time walking
Let j = time jogging


Method___________speed_________time____________distance
walk_____________4_____________(w)___________(4w)
jog______________7_____________(j)___________(7j)
TOTAL__________________________2________________11.6


EQUATIONS:  {{{w+j=2}}} and {{{4w+7j=11.6}}}
Solve for w and j.

The time sum equation can also be {{{4w+4j=8}}} and then this can be subtracted from the distance sum equation.
{{{(4w+7j)-(4w+4j)=11.6-8}}}
{{{7j-4j=3.6}}}
{{{3j=3.6}}}
{{{highlight(j=1.2)}}} HOURS jogging
Using that in the original time sum equation, {{{highlight(w=0.8)}}} HOURS walking.


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That is jogging: 1 hour 12 minutes, and 
walking: 48 minutes
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HOW FAR WALING & JOGGING?
rate*time=distance again.
Walking is 4*0.8=3.2 miles
Jogging is 7*1.2=8.4 miles
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