Answer:
Cabrina's time = 5 hours
Dabney's time = 6.5 hours
Step-by-step explanation:
The data of the exercise are:
Cabrina speed = 75 mph
Daney speed = 60 mph
The sum of their distance is 765 miles, therefore
Cabrina's distance Dabney's distance = 765
Cabrina's distance = x
Dabney's distance = 765-x
The sum of their times is 11.5 hours, therefore
Cabrina's time Dabneys time = 11.5
Cabrina's time = x / 75
Dabney's time = (765-x) / 60
x / 75 (765-x) / 60 = 11.5
Lowest common denominator of 75 and 60 is 300, therefore we have:
330 * x / 75 300 * (765-x) / 60 = 300 * 11.5
4 * x 5 * (- x 765) = 3450
4 * x - 5 * x 3825 = 3450
x = 375
Replacing:
Cabrina's time = 375/75 = 5 hours took
Dabney's time = (765-375) / 60 = 6.5 hours took