How many minutes does Aditya take to cover a distance of 400 m, if he runs at a speed of 20 km/hr? [Bank P.O. 2000]
A cyclist covers a distance of 750 m in 2 min 30 sec. What is the speed in km/hr of the cyclist?
A dog takes 4 leaps for every 5 leaps of a hare but 3 leaps of a dog are equal to 4 leaps of the hare. Compare their speeds.
Answer & Solution
Answer: c) 16 : 15
Solution: Let the distance covered in 1 leap of the dog be x and that covered in 1 leap of the hare be y. Then, 3x = 4y => x = 4/3 y => 4x = 16/3 y. Ratio of speeds of dog and hare = Ratio of distance covered by them in the same time = 4x : 5y = 16/3 y : 5y = 16/3 : 5 = 16 : 15
While covering a distance of 24 km, a man noticed that after walking for 1 hour and 40 minutes, the distance covered by him was 5/7 of the remaining distance. What was his speed in metres per second? [R.R.B. 2002]
Answer & Solution
Answer: c) 1 2/3 m/sec.
Solution: Let the speed be x km/hr. Then, distance covered in 1 hr 40 min i.e., 1 2/3 hrs = 5x/3 km. Remaining distance = [24 - (5x/3)] km. 5x/3 = 5/7 [24 - (5x/3)] => 5x/3 = 5/7 [(72 - 5x) / 3] => 7x = 72 - 5x => 12x = 72 => x = 6 Hence, Speed = 6 km/hr = [6 * (5/18)] m/sec = 5/3 m/sec = 1 2/3 m/sec.
Peter can cover a certain distance in 1 hr. 24 min. by covering two-third of the distance at 4 kmph and the rest at 5 kmph. Find the total distance.
A man travelled from the village to the post-office at the rate of 25 kmph and walked back at the rate of 4 kmph. If the whole journey took 5 hours 48 minutes, find the distance of the post-office form the village. [S.S.C 2004]
An aeroplane flies along the four sides of a square at the speeds of 200, 400, 600 and 800 km/hr. Find the average speed of the plane around the field.