The angle of elevation of a 5 m long ladder leaning against a wall is 45 degrees and the foot of the ladder is 3 m away from the…
Quantitative Aptitude ·Previously asked in JKSSB Sub Inspector (Executive) 2017
View the full solved paper: JKSSB Sub Inspector (Executive) 2017
Question
The angle of elevation of a 5 m long ladder leaning against a wall is 45 degrees and the foot of the ladder is 3 m away from the wall. The height of the wall up to the point where the ladder is resting against it is:
- A. 2 m
- B. 3 m
- C. 4 m (Correct answer)
- D. Cannot be determined on the basis of the given information
Correct Answer
Option C — 4 m
Detailed Solution & Explanation
The correct answer is 4 m.
Key Points
- The ladder is 5 m long, foot is 3 m from the wall, angle of elevation = 45°.
- Using Pythagoras: height² = 5² − 3² = 25 − 9 = 16 → height = 4 m. Note: the problem states angle = 45° but the geometry (3-4-5 right triangle) gives angle = arctan(4/3) ≈ 53°.
- The answer from Pythagorean theorem is 4 m.
Topics covered: JKPSI JKSSB 2017 Quantitative Aptitude Geometry Trigonometry