Bad weather caused an aeroplane to slow down on a 600-kilometer journey. The flight's average speed was lowered by 200 km/hr, and the flight time was increased by 30 minutes. The flight will last for the following time:
A. 1 hour
B. 2 hours
C. 3 hours
D. 4 hours
Answer:A
Bad weather caused an aeroplane to slow down on a 600-kilometer journey. The flight's average speed was lowered by 200 km/hr, and the flight time was increased by 30 minutes. The flight will last for the following time:
A. 1 hour B. 2 hours C. 3 hours D. 4 hours
Explanation: Let's say the flight is x hours long.After that, 600/x - 600/x + (1/2) = 200,200 = 600/x - 1200/2x + 1,3 = x(2x + 1),0 = 2x2 + x - 3,0 = (2x + 3)(x - 1),1 hour = x [by ignoring x's -ve value].