Three numbers are in the ratio 3:5:6. If the sum of their squares is 630, then the numbers are:
Let the numbers be 3x, 5x and 6x respectively. ⇒ (3x)2+ (5x)2+ (6x)2= 630 ⇒ 9x2+ 25x2+ 36x2= 630 ⇒ 70x2= 630 ⇒ x2= 9 ⇒ x = 3 ∴ Numbers are 9, 15 and 18.
A motor car travels a distance of 180 km at the speed of 20 kmph. If it covers the next 100 km of its journey at the speed of 20 kmph and last 40 km of ...
A train 420 metre long takes 21 sec to cross a man running at a speed of 3 km/hr in the direction same to that of train. What is the speed of the train?
Two trains approach each other at 23 kmph and 26 kmph from 2 places 245 km apart. After how many hours they will meet?
A man running at the speed of 6 kmph was over taken by the train moving with the speed of 42 kmph in 26 seconds. Find the length of train.
Two trains of same length are running in parallel tracks in the same direction with speed 26 km/hr and 80 km/hr respectively. The latter completely cros...
Train A takes 90 seconds to cross a telegraph pole by travelling at 18 kmph speed. Train B has its length 60% more than A. It takes 40 seconds to cross ...
Train A running at speed of 72 km/hr crosses a platform having twice the length of train in 18 sec. Train B whose length is 300m crosses same platform i...
1200 metres long train crosses a man who is moving in the same direction with a certain speed in 25 seconds. If the same train can cross a pole in 20 se...
A person sees a train passing over 2 km long bridge. The length of the train is half that of bridge if the train clears the bridge in 6 mins. What is th...
Two trains, A and B, cross each other in 15 seconds and 35 seconds respectively, when running in opposite and the same direction respectively. If the sp...
