Question 247435
The whole trip took 1.5 hrs.
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d=rt, so t = d/r
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1.5 = 12/x + 12/3x
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Multiply both sides by 3x.
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3x(1.5) = (3x*12)/x + (3x*12)/3x
4.5x = 36 + 12
4.5x = 48
x = 10.667 or 10+2/3
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So, this suggests her walking speed is 10+2/3 blocks/hr and her jogging speed is 32 blocks/hr.
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Checking our work,
12 = 10.667t
10.667t = 12
t = 12/10.667
t = 1.125 hr walking
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12 = 32t
32t = 12
t = 12/32 = .375 hr jogging
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1.125 + .375 = 1.5 hr total
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OK