Subject
Quantitative Aptitude
Topic
Speed & Distance
A person wishes to reach his destination 90 km away in 3 hours but for the first half of the journey his speed was 20 km/hr. His average speed for the rest of the journey should be
A person wishes to reach his destination 90 km away in 3 hours but for the first half of the journey his speed was 20 km/hr. His average speed for the rest of the journey should be
ক)
40 km/hrখ)
0.75 km/minগ)
1 km/minঘ)
None of theseExplanation
(প্রশ্ন- একজন লোক তাঁর ৯০ কিলোমিটারের পথ তিন ঘন্টায় পাড়ি দিতে চাইল । কিন্তু, যাত্রার প্রথমার্ধে তাঁর গতি ছিল ঘন্টায় 20 কিলোমিটার । বাকি অর্ধেক পথে তাঁর গড় গতি কত হতে হবে?) লোকটিকে 3 ঘন্টায় 90 km পথ যেতে হবে যাত্রার প্রথমার্ধে অর্থাৎ (90/2) km = 45 km দূরত্ব 20 km/hr গতিতে চলে প্রথমার্ধে সময় লাগে = দূওরত্ব/বেগ = 45/20 ঘন্টায় = 9/4 ঘন্টায় = 2 (1/4) ঘন্টায় = 2 hr 15 min. ∴বাকি সময় = (3 - 2hr 15 min ) = 45 min ∴ বাকি পথে তাঁর গতি হবে = (45/45) = 1 km/min =Related questions
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