A man completes 2/25 of a journey by bus, 21/50 by car, and the remaining 2 km on foot. What is the total distance of the journey (in km)?

Introduction / Context:
Part-by-part distance problems often provide fractional segments plus a fixed remainder. Sum the fractions to find what part of the journey the fixed remainder represents, then scale to get the total distance.

Given Data / Assumptions:

• Bus fraction = 2/25.
• Car fraction = 21/50.
• Foot distance = 2 km (remaining).

Concept / Approach:
Total fractional part done by bus + car = 2/25 + 21/50 = 4/50 + 21/50 = 25/50 = 1/2. Hence remaining half equals 2 km ⇒ total is 4 km.

Step-by-Step Solution:

Verification / Alternative check:
Half of 4 km is 2 km, matching the on-foot segment.

Why Other Options Are Wrong:
2.7/3.4/3.8 km would not leave exactly 2 km as one half.

Common Pitfalls:
Failing to convert 2/25 to 4/50 before addition.

Final Answer:
4 km