General Science – Unit conversion (distance) Question: One kilometre (km) is equal to how many miles (mi)?

Introduction / Context:This question checks basic unit conversion between the metric system and the imperial/US customary system. Converting kilometres (km) to miles (mi) is common in travel, navigation, athletics, and everyday life, so remembering the standard factor helps you estimate distances accurately.

Given Data / Assumptions:

• We want miles (mi) for a distance of exactly 1 kilometre (km).
• Use the standard conversion factor: 1 km ≈ 0.621371 mi.
• Options are rounded to two decimal places, so the nearest correct choice is required.

Concept / Approach:To convert from kilometres to miles, multiply by the constant factor miles_per_km. The widely accepted factor is 0.621371. When options present rounded values, choose the one that reasonably approximates the precise result.

Step-by-Step Solution:Let distance_km = 1.Use miles_per_km = 0.621371.Compute miles: miles = distance_km * miles_per_km.miles = 1 * 0.621371 = 0.621371.Round to two decimals for comparison with options: 0.621371 ≈ 0.62.

Verification / Alternative check:Recall the inverse factor: 1 mile ≈ 1.609 km. Therefore, 1 km ≈ 1 / 1.609 ≈ 0.621, which matches 0.62 to two decimals.

Why Other Options Are Wrong:

• 0.84: Too high; would imply 1 km is almost one mile, which is incorrect.
• 0.5: Too low; half a mile is about 0.805 km, not 1 km.
• 1.6: This is approximately km per mile, not miles per km.

Common Pitfalls:Mixing up the direction of conversion factors (using 1.609 instead of 0.621 for km → mi) or rounding too aggressively. Keep two decimals for quick estimations.

Final Answer:0.62