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Kyle rowed his boat upstream for 50 minutes, and it took him 30 minutes to row back downstream. His speed going upstream is two miles per hour slower than his speed going downstream. Find Kyle’s upstream and downstream speeds.

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Final answer:

To find Kyle’s upstream and downstream speeds, we set up a system of equations based on the given information. Solving these equations, we find that Kyle’s downstream speed is 5 mph and his upstream speed is 3 mph.

Step-by-step explanation:

To find Kyle's upstream and downstream speeds, we can set up a system of equations based on the given information.

Let's say Kyle's speed going downstream is x miles per hour. This means his speed going upstream is x - 2 miles per hour, as stated in the question.

Now, let's use the concept of speed = distance/time to form our equations:

  1. When rowing upstream, Kyle covers a certain distance in 50 minutes, which is 50/60 = 5/6 hours. So, his speed going upstream is (distance)/(time) = (distance)/((5/6)) = 6(distance)/5 = (x - 2) miles per hour.
  2. When rowing downstream, Kyle covers the same distance in 30 minutes, which is 30/60 = 1/2 hours. So, his speed going downstream is (distance)/(time) = (distance)/((1/2)) = 2(distance) miles per hour.

Now we have two equations:

  1. (x - 2) = 6(distance)/5
  2. 2(distance) = x

We can solve these equations simultaneously to find the values of x and the distance. Let's solve equation 1 for distance:

  1. Since (x - 2) = 6(distance)/5, we can rearrange it to (x - 2) x (5/6) = distance.

Now, plug this value of distance into equation 2 and solve for x:

  1. Using the value of distance from equation 3 in equation 2, we get 2((x - 2) x (5/6)) = x.
  2. Simplifying this equation, we have 10(x - 2) = 6x.
  3. Expanding and rearranging, we get 10x - 20 = 6x.
  4. Combining like terms, we have 4x - 20 = 0.
  5. Adding 20 to both sides, we get 4x = 20.
  6. Dividing by 4, we get x = 5.

Now that we have found x, which represents Kyle's speed going downstream, we can substitute it back into equation 2 to find the distance:

  1. (2 x distance) = 5.
  2. Simplifying, we get distance = 5/2 = 2.5 miles.

Therefore, Kyle's downstream speed is 5 miles per hour and his upstream speed is 3 miles per hour.

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