A plane left 30 minutes late than its scheduled time and in order to reach the destination
Quadratic Equations (10)A plane left 30 minutes late than its scheduled time and in order to reach the destination 1500 km away in time, it had to increase its speed by 100 km/h from the usual speed. Find its usual speed.
Answer
Let the usual speed of the plane be x km/hr.
$$ \frac{1500}{x} - \frac{1500}{x + 100} = \frac{30}{60} $$
x2 + 100x - 300000 = 0
x2 + 600x - 500x - 300000 = 0
(x + 600)(x - 500) = 0
$ x \ne - 600, ∴ x = 500 $
Speed of plane = 500 km/hr
Exam Year:
2018
Related Questions
- A train travels at a certain average speed for a distance of 63 km and then travels at a distance of 72 km
- A motor boat whose speed is 18 km/hr in still water takes 1hr more to go 24 km
- If x = 3 is one root of the quadratic equation
- Which of the following is not a quadratic equation
- Write all the values of p for which the quadratic equation $x^2 + px + 16 = 0$
- A quadratic equation whose one root is 2 and the sum of whose roots is zero, is