Question

pls help in this question​

Answer 1

Answer:

750 km/hr

Step-by-step explanation:

Let the usual speed of the plane = x km/hr

Distance to the destination = 1500 km

Increased speed = 250 km/hr

So, according to the question

1500/x - 1500/(x + 250) = 30/60

⇒ x² + 250x = 750000

⇒ x² + 250x - 750000 = 0

⇒ x² + 1000x - 750x - 750000 = 0

⇒ x(x + 1000) - 750(x + 1000) = 0

⇒ (x - 750)(x + 1000) = 0

⇒ x = 750, -1000{Speed cannot be negative}

⇒ x = 750 km/hr

Therefore,

Usual speed of plane is 750 km/hr.

Hope it helps!