A boat can travel 20 km upstream in 5 hours. If the speed of the stream is 3 km/

₹0.0

Question: A boat can travel 20 km upstream in 5 hours. If the speed of the stream is 3 km/h, what is the speed of the boat in still water?

Options:

Correct Answer: 7 km/h

Solution:

Speed upstream = 20 km / 5 h = 4 km/h. Let speed of boat = x, then x - 3 = 4, so x = 7 km/h.

A boat can travel 20 km upstream in 5 hours. If the speed of the stream is 3 km/h, what is the speed of the boat in still water?

A boat can travel 20 km upstream in 5 hours. If the speed of the stream is 3 km/h, what is the speed of the boat in still water?

Step 1: Calculate the speed of the boat going upstream. The boat travels 20 km in 5 hours.
Step 2: Use the formula for speed: Speed = Distance / Time. So, Speed upstream = 20 km / 5 h = 4 km/h.
Step 3: Let the speed of the boat in still water be 'x' km/h.
Step 4: The speed of the stream is given as 3 km/h.
Step 5: When the boat is going upstream, its effective speed is reduced by the speed of the stream. So, the equation is: x - 3 = 4.
Step 6: Solve the equation for 'x': Add 3 to both sides: x = 4 + 3.
Step 7: Calculate x: x = 7 km/h. This is the speed of the boat in still water.

Relative Speed – Understanding how the speed of a boat is affected by the speed of the stream when traveling upstream or downstream.
Algebraic Manipulation – Using algebra to solve for the unknown variable, in this case, the speed of the boat in still water.