word problem: 500 miles apart, then how fast were they going

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Well here it is...

J. Bond and E. Blofeld are driving speedboats in opposite directions after a failed attempt by the latter to blow up the world with a nuclear bomb. Mr. Bond’s boat is going 25 MPH faster than Mr. Blofeld’s. After 3 hours they are 500 miles apart. How fast was each of them going?

Thanks!
 
Use the usual "uniform rate" formula, "distance equals rate times time", or "d = rt". Note that, since they are going in opposite directions, their distances add together.

Pick a variable to stand for the slower rate. Write an expression, in terms of this variable, for the faster rate.

After t = 3, what is the expression for their total distance apart? Set this equal to "500", and solve.

If you get stuck, please reply showing how far you have gotten. Thank you.

Eliz.
 
d = rt
d = 500
r (slower boat) = x
r (faster boat) = x + 25
t = 3

500 = 3 (x + x + 25)
500 = 3 (2x + 25)
500 = 6x + 75
425 = 6x
x = 70.83 mph
x + 25 = 95.83 mph

Yes or no?
Thanks!!
 
To check the answer to any "solving" exercise, plug your solution back into the original problem, and see if it works. If the two travelled at those rates, how far would they get in three hours?

Eliz.
 
The slow boat would go 212.49 miles and the fast boat 287.49 miles which is 499.98 miles travelled (which is pretty darn close to 500; because of rounding). My guess is that I actually got this one right.

Yeah :D I hope!!
Andrea
 
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