A man covers 30 km of his journey at 10 km/h and the remaining 40 km at 20 km/h. Find his average speed for the whole journey. MCQ with Answer and Explanation
A man covers 30 km of his journey at 10 km/h and the remaining 40 km at 20 km/h. Find his average speed for the whole journey.
A. 12 km/h
B. 16 km/h
C. 15 km/h
D. 14 km/h
Answer: Option D
Solution (By JKSSB Mock Tests)
Total distance = 30 + 40 = 70 km. Time for first part = 30 / 10 = 3 hours. Time for second part = 40 / 20 = 2 hours. Total time = 5 hours. Average speed = 70 / 5 = 14 km/h.
If a student walks from his house to school at 5 km/h, he is late by 10 minutes. However, if he walks at 6 km/h, he is late by only 2 minutes. Find the distance between his house and school.
No comments yet. Be the first to start the discussion!