SOLUTION: Hey! So I know you have to use the distance formula and everything on this problem but it's been a while since I've had to use it. The problem is: two cars travel in opposite direc
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Question 1044481: Hey! So I know you have to use the distance formula and everything on this problem but it's been a while since I've had to use it. The problem is: two cars travel in opposite directions. One travels 20mph slower than the other. After 3 hours, they are 270 miles apart. How fast is each car going? Found 2 solutions by Boreal, solver91311:Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! The way I do this is that the cars are going in opposite directions and after 3 hours they are 270 miles apart.
270 miles/3 hours=90 miles/ hour is the separation speed and that is the combined speed of both cars. Therefore,
car a+car b=90
but car a -20=car b, which means that car b is 20 mph slower than car a
substitute into the first equation.
car a+car a-20=90
2 car a=110
car a=55 mph
car b=55-20, or 35 mph
check
In 3 hours, car a has gone 55*3=165 miles
car b has gone 35*3=105 miles
They add to 270 miles
If they are 270 miles apart after 3 hours, then they are getting further apart at a rate of 90 miles per hour. Since they are travelling in opposite directions, their individual speeds add to obtain the relative speed between them. If is the speed of the faster car, and the other car is going 20 miles per hour slower, then the speed of the slower car has to be , and their combined speed must be . Solve
for then calculate
John
My calculator said it, I believe it, that settles it
