Subject
Quantitative Aptitude
Topic
Speed & Distance
A man travels 600 km by train at 80 km.hr, 800 km by ship at 40 km/hr, 500 km by airplane at 400 km/hr and 100 km by car at 50 km/hr. What is the average speed for the entire distance ?(একজন ব্যক্তি ট্রেনে চেপে 600 km দূরত্ব 80 km/hr বেগে, জাহাজে চেপে 800 km দূরত্ব 40 km/hr বেগে, উড়োজাহাজে চেপে 500 km দূরত্ব 400 km/hr বেগে এবং কারে চেপে 100 km দূরত্ব 50 km/hr বেগে ভ্রমণ করে । সমগ্র দূরত্বে তাঁর গড় বেগ (average speed) কত ?)
A man travels 600 km by train at 80 km.hr, 800 km by ship at 40 km/hr, 500 km by airplane at 400 km/hr and 100 km by car at 50 km/hr. What is the average speed for the entire distance ?(একজন ব্যক্তি ট্রেনে চেপে 600 km দূরত্ব 80 km/hr বেগে, জাহাজে চেপে 800 km দূরত্ব 40 km/hr বেগে, উড়োজাহাজে চেপে 500 km দূরত্ব 400 km/hr বেগে এবং কারে চেপে 100 km দূরত্ব 50 km/hr বেগে ভ্রমণ করে । সমগ্র দূরত্বে তাঁর গড় বেগ (average speed) কত ?)
ক)
60 km/hrখ)
60(5/123)km/hrগ)
62 km/hrঘ)
65(5/123)km/hrExplanation
মোট দূরত্ব = ( 600+800+500+100) = 2000 km আবার, বেগ = (দূরত্ব/সময়) বা, সময়=(দূরত্ব/বেগ) ∴ মোট সময় = (600/80)+(800/40)+(500/400)+(100/50) = {(15/2)+20+(5/4)+ 2} = {(30+80+5+8)/4} = (123/4) ∴ গড় বেগ = (মোট দূরত্ব/মোট সময়) = {2000÷(123/4)} = {2000×(4/123)} =65.041 km/hrRelated questions
A man takes twice as long to row a distance against the stream as to row the same distance in favour of the stream. The ratio of the speed of the boat (in still water) and the stream is:Speed of a boat in standing water is 9 kmph and the speed of the stream is 5 kmph. A man rows to a place at a distance of 105 km and comes back to the starting point. The total time taken by him is:two trains are moving in opposite directions at 60 km/hr and 90 km/hr. Their lengths are 1/10 km and 9 km respectively. The time taken by slower train to cross the faster train in seconds is -A man can row three-quarters of a kilometre against the stream in 11×(1/4) minutes and down the stream in 7×(1/2) minutes. The speed (in km/hr) of the man in still water is:In a 300 m race A beats B by 5 metre or 6 seconds. B's time over the course is -A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water?A boat covers a certain distance downstream in 1 hour, while it comes back in 1x(1/2) hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water?A man buys tk 20 shares paying 9% dividend. The man wants to have an interest of 12% on his money. The market value of each share is-