Due to inclement weather, an Aeroplane reduce its speed by 300 km/hr and reached the destination of 1200 km late by 2 hours. Then the schedule duration of the flight was :

Answer: Option C

Solution

Answer: Option C

Solution:

Let the original speed of Aeroplane be x km/hr
$$\begin{array}{rl}& \frac{1200}{\left(x-300\right)}-\frac{1200}{x}=2\\ & \frac{x-x+300}{\left(x-300\right)x}=\frac{2}{1200}\end{array}$$

Original time :
$$\begin{array}{rl}& t=\frac{1200}{600}\\ & t=2\text{ hours}\end{array}$$