In a flight of 600 km , an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by $200~km/hr$ and the time of flight consequently increased by 30 minutes. The duration of the flight was:

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Accepted Answer

সঠিক উত্তর: । ব্যাখ্যা: Let, speed be S and time be T. Now, $ST=600$. Again, $(S-200)*(T+0.5)=600$. Or, $ST - 200T + 0.5S - 100 = 600$. Or, $200T - 0.5S + 100 = 0$. Or, $200 T^2 + 100 T - 300 = 0$; $[S=600/T]$. Or, $2T^2 + T - 3 = 0$. Or, $(2T+3)(T-1)=0$. Or, $T = -3/2, 1$. So, flight টির duration ছিলো $1 + 0.5$ hours = $1.5$ hours.

In a flight of 600 km , an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by \(200~km/hr\) and the time of flight consequently increased by 30 minutes. The duration of the flight was: