Bonnie drove 540 miles in three times the time it took Buffy

Bonnie drove 540 miles in three times the time it took Buffy to travel 135 miles. Buffy\'s speed was slower than Bonnie\'s by 15 miles per hour. Frind the rate and time of each

Solution

Bonnie DATA:
distance=540 miles ; time= 3x hours; rate= d/t= 540/3x= 180/x mph
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Buffy DATA:
distance=135 miles ; time = x hours ; rate = d/t= 135/x mph
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EQUATION:
Buffy rate+15 = Bonnie rate
135/x + 15 = 180/x
Multiply thru by x to get:
135 + 15x = 180
15x=45
x=3 hrs (Buffy time); Buffy rate=135/3=45 mph
Bonnie time= 3x = 9 hrs: Bonnie rate=180=x=180/3=60 mph