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- Identify upstream or downstream.
- Apply the correct effective speed.
- Use distance/time relation.
Correct Answer: A
Correct Answer: A
Method / Topic: Boats and Streams
The answer uses the correct effective speed of the boat.
Short Explanation
Detailed Explanation
Correct Answer: A
Method / Topic: Boats and Streams
<table cellspacing="0" style="border-collapse:collapse; height:20px; width:85px">
<tbody>
<tr>
<td style="border-bottom:none; border-left:none; border-right:none; border-top:none; height:20px; vertical-align:top; white-space:normal; width:85px"><span style="color:#000000">Calculate upstream and downstream times separately using speeds 15 and 21 km/h. Their difference is 4.2-3=1.2 hours.</span></td>
</tr>
</tbody>
</table>
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Learn + Solve: Shortcut, Trap & Fast Route Click to view shortcut, steps, and common mistake
Shortcut used, common trap, and the fastest solving route
- Identify upstream or downstream.
- Apply the correct effective speed.
- Use distance/time relation.
A boat moves at 18 km/h in still water and the stream speed is 3 km/h. What is the difference between the times taken to cover 63 km upstream and downstream?
Explanation
Correct Answer: A
Method / Topic: Boats and Streams
The answer uses the correct effective speed of the boat.
Short Explanation
Detailed Explanation
Correct Answer: A
Method / Topic: Boats and Streams
<table cellspacing="0" style="border-collapse:collapse; height:20px; width:85px">
<tbody>
<tr>
<td style="border-bottom:none; border-left:none; border-right:none; border-top:none; height:20px; vertical-align:top; white-space:normal; width:85px"><span style="color:#000000">Calculate upstream and downstream times separately using speeds 15 and 21 km/h. Their difference is 4.2-3=1.2 hours.</span></td>
</tr>
</tbody>
</table>
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