Two buses start from the same depot. Bus A goes 27 km West, then turns to its…

2024

Two buses start from the same depot. Bus A goes 27 km West, then turns to its right and goes 43 km. In the meanwhile Bus B goes 19 km North, then turns West and goes 61 km, then turns to its right and goes 24 km. Where is Bus B with respect to Bus A?

  1. A.

    34 km East

  2. B.

    88 km West

  3. C.

    88 km East

  4. D.

    34 km West

Show answer & explanation

Correct answer: D

Concept: In a direction-sense problem, place the common starting point at the origin of an East-West / North-South coordinate system, with East and North as the positive axes. Track each moving object leg by leg, using the rule that a right turn rotates the current facing direction 90° clockwise (North → East → South → West → North). The relative position of one object with respect to another is then simply the difference between their final coordinates.

Application:

  1. Take the depot as the origin (0, 0) for both buses, with East and North as the positive directions.

  2. Bus A moves 27 km West: its position becomes 27 km West, 0 km North.

  3. Bus A turns right — facing West, a right turn points it North — and moves 43 km: its position becomes 27 km West, 43 km North.

  4. Bus B moves 19 km North: its position becomes 0 km West, 19 km North.

  5. Bus B turns and moves 61 km West: its position becomes 61 km West, 19 km North.

  6. Bus B turns right — facing West, a right turn points it North — and moves 24 km: its position becomes 61 km West, 19 + 24 = 43 km North.

Cross-check: comparing the two buses' final coordinates:

Bus

East-West position (from depot)

North-South position (from depot)

Bus A

27 km West

43 km North

Bus B

61 km West

43 km North

Both buses sit exactly 43 km North of the depot, so they lie on the same east-west line — the entire separation between them is therefore horizontal. Bus B's westward leg (61 km) exceeds Bus A's westward leg (27 km) by 34 km, so Bus B lies 34 km further west than Bus A.

Hence, Bus B is 34 km West of Bus A.

Explore the full course: Amcat Preparation