Naira paddled 4.5km with the current in the same amount of time as it took her to paddle 3km against the current. Naira paddled at an average rate of 5hkm relative to the water each way. Assume the speed of the current was constant.What was the speed of the current?□hkm
Q. Naira paddled 4.5km with the current in the same amount of time as it took her to paddle 3km against the current. Naira paddled at an average rate of 5hkm relative to the water each way. Assume the speed of the current was constant.What was the speed of the current?□hkm
Denote current speed: Let's denote the speed of the current as c (km/h). Naira's speed relative to the water is 5 km/h. When paddling with the current, her effective speed is (5+c) km/h, and when paddling against the current, her effective speed is (5−c) km/h. We know that the time taken to paddle in both directions is the same. We can use the formula time=speeddistance to set up our equation.
Calculate time with current: First, let's write down the time it takes Naira to paddle with the current: time_with_current=speed_with_currentdistance_with_current. This gives us time_with_current=(5km/h+c)4.5km.
Calculate time against current: Now, let's write down the time it takes Naira to paddle against the current: time_against_current=speed_against_currentdistance_against_current. This gives us time_against_current=(5km/h−c)3km.
Set up equation: Since the times are equal, we can set the two expressions equal to each other: (5km/h+c)4.5km=(5km/h−c)3km.
Cross-multiply to solve: To solve for c, we cross-multiply: (4.5km)×(5km/h−c)=(3km)×(5km/h+c).
Expand and simplify equation: Expanding both sides of the equation gives us: 4.5×5−4.5c=3×5+3c.
Combine like terms: Simplify the equation: 22.5−4.5c=15+3c.
Divide to solve for c: Now, let's combine like terms by adding 4.5c to both sides and subtracting 15 from both sides: 22.5−15=3c+4.5c.
Final result: This simplifies to: 7.5=7.5c.
Final result: This simplifies to: 7.5=7.5c. Finally, divide both sides by 7.5 to solve for c: c=7.57.5.
Final result: This simplifies to: 7.5=7.5c. Finally, divide both sides by 7.5 to solve for c: c=7.57.5. This gives us: c=1 km/h.
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