<PRE><B>Question 190998</B>
Zoha jogs 3 miles per hour faster than she walks. She jogs for 2 miles and then 
walks for 2 miles. If the total time of her outing is one hour, find the rate at
 which she walks and jogs?
:
Let x = walking speed
then
(x+3) = jogging speed
:
Write a time equation; Time = {{{dist/speed}}}
:
walk time + jog time = 1 hr
{{{2/x}}} + {{{2/((x+3))}}} = 1
:
Multiply equation by x(x+3), results:
2(x+3) + 2x = x(x+3)
2x + 6 + 2x = x^2 + 3x
4x + 6 = x^2 + 3x
0 = x^2 + 3x - 4x - 6
a quadratic equation:
x^2 - x - 6 = 0
Factors to
(x-3)(x+2) = 0
Positive solution
x = 3 mph is the walking speed
then
3 + 3 = 6 mph is the jogging speed
:
:
Check solution:
2/3 + 2/6 = 1
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