Q. A plane flies along the four sides of a square field at a speed of 200, 400, 600 and 800 km/hr. Then find the average speed of plane around the square field.
β
Correct Answer: (D)
384
Explanation: Let the side of the square field be x and the average speed of plane be y
x/200 + x/400 + x/600 + x/800 = 4x/y
⇒ 25x/2400 = 4x/y
⇒ y =384
∴ Average speed is 384 km/hr
x/200 + x/400 + x/600 + x/800 = 4x/y
⇒ 25x/2400 = 4x/y
⇒ y =384
∴ Average speed is 384 km/hr
Explanation by: Rohan Raj
Let the side of the square field be x and the average speed of plane be y
x/200 + x/400 + x/600 + x/800 = 4x/y
⇒ 25x/2400 = 4x/y
⇒ y =384
∴ Average speed is 384 km/hr
x/200 + x/400 + x/600 + x/800 = 4x/y
⇒ 25x/2400 = 4x/y
⇒ y =384
∴ Average speed is 384 km/hr