Question

Martina swam 4 kilometers against the current in the same amount of time it took her to swim 12 kilometers with the current. The rate of the current was 2 kilometers per hour. How fast would Martina swim if there were no current

Answer 1

Martina would swim at a speed of 10 km/h if there were no current.

Step-by-step explanation:

To find out how fast Martina would swim if there were no current, we need to calculate her swimming speed without the effect of the current. Let's denote her swimming speed as 'x' km/h.

When swimming against the current, her effective speed is x - 2 km/h (since the current is working against her), and when swimming with the current, her effective speed is x + 2 km/h (since the current is helping her).

According to the problem, Martina swims 4 kilometers against the current in the same time it takes her to swim 12 kilometers with the current. This means that the time it takes to travel 4 kilometers, swimming against the current at x - 2 km/h, is equal to the time it takes to travel 12 kilometers, swimming with the current at x + 2 km/h.

Using the formula time = distance / speed, we can set up the following equation:

4 / (x - 2) = 12 / (x + 2)

Solving this equation will give us the value of x, which is Martina's swimming speed without the current. Solving the equation, we find that the value of x is 10 km/h.

Therefore, Martina would swim at a speed of 10 km/h if there were no current.