On a scale of map, 0.6 cm represents 6.6 km. If the distance between the points on the map is 80.5 cm, the actual distance between these points is
Aptitude
Unitary Method
Difficulty: Easy
Choose an option
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A9 km
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B72.5 km
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C190.75 km
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D885.5 km
Answer
Correct Answer: 885.5 km
Explanation
### Concept & Scaling in Maps
Map scales represent a direct ratio between the distance on the map and the actual distance on the ground.
$$ \text{Actual Distance} = \text{Map Distance} \times \left( \frac{\text{Actual Scale Reference}}{\text{Map Scale Reference}} \right) $$
### Step-by-Step Solution
* Given: Map scale is 0.6 cm = 6.6 km.
* Calculate the actual distance represented by 1 cm on the map: $\frac{6.6}{0.6} = 11$ km.
* Given map distance between points = 80.5 cm.
* Actual distance = $80.5 \times 11 = 885.5$ km.
### Exam Strategy & Shortcut
Multiply $80.5 \times 11$ quickly using the 11-multiplication trick. Split the numbers: $805 \times 11$. $8 | 8+0 | 0+5 | 5 \rightarrow 8855$. Add the one decimal place back to get $885.5$.
### Common Pitfall
Setting up the ratio upside down or incorrectly dealing with the decimals in $0.6$ and $6.6$, which could lead to answers off by a factor of 10.
### Final Answer
Therefore, the correct answer is **885.5 km**.