pls solve this question plss
Answers
Answer:
Answer is 750 kmph.
.
Since, Speed = distance/ time.
s= d/t
.
Now assume that, initially speed was 's' kmph and the time taken to cover a distance of d=1500 kms was 't' hours.
So, s= 1500/t. --------(i)
.
Now, we know that, the new speed was 's+ 250' kmph and the time taken to cover the distance of d=1500 kms was 't- 0.5' hours, i.e. half an hour less time.
So, s+ 250= 1500/ (t- 0.5). ----------(ii)
.
Now, we have 2 equations. On solving them, we get,
initial time= t= 2 hours. Initial speed= s= distance/time= 1500/2= 750kmph.
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
⇒ 1500 * 60 * (x + 250) - 1500 * 60 * x = 30 * x * (x + 250)
⇒ 90000(x + 250) - 90000x = 30x(x + 250)
⇒ 90000x + 22500000 - 90000x = 30x² + 7500x
⇒ 30x² + 7500x - 22500000 = 0
⇒ 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 is 750 km/hr.
Hope it helps!