Don L. answered 12/13/16
Tutor
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Fifteen years teaching and tutoring basic math skills and algebra
Hi Taghrid, this is a D(istance) = R(ate) * T(ime) problem. We know the distance traveled is 14.8 miles. We also know the time they walk is 4 hours. Last we know that Ben walks .9 mph faster than Alan.
We can set up an equation based on D = R * T.
Let x be the rate for Alan, then x + .9 is the rate for Ben.
The distance Alan covers in 4 hours is: 4x.
The distance Ben covers in 4 hours is: 4 * (x + .9)
The total distance traveled by both is 14.8 miles.
The equation:
4x + 4 * (x + .9) = 14.8
4x + 4x + 3.6 = 14.8
Combine terms and subtract 3.6 from both sides:
8x = 11.2
Divide both sides by 8:
x = 1.4
Alan's rate of travel is 1.4 mph.
Ben's rate of travel is 1.4 + .9, or 2.3 mph.
Check:
4 * 1.4 + 4 * (1.4 + .9) = 14.8
5.6 + 9.2 = 14.8
14.8 = 14.8
Values check.
Questions?