Question

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 /hr from the usuall speed find its usual speed

Answer 1

Answer:

Step-by-step explanation:

Solution :-

Let the usual speed of the plane be x km/hr.

Increased speed = 100 km/hr

Time taken to cover 1500 km = 1500/x hr.

Time taken to cover 1500 km with increased speed = 1500/x + 100 hr

According to the Question,

⇒ 1500/x - 1500(x + 100) = 30/60

⇒ x² + 100x - 300000 = 0

⇒ x² + 600x - 500x - 300000 = 0

⇒ (x + 600)(x - 500) = 0

⇒ x = -600 or 500 (Neglecting negative sign as speed cannot be negative)

⇒ x = 500

Hence, the usual speed of plane is 500 km/hr.

Answer 2

Answer:

ANSWER IS 500km/hr

as we know that let the speed of a plane be X per hour

time taken to cover 1500 km

as t1 equal to distance upon speed so it is equal to 1500 upon x

now t2 is equal to 1500 upon X + hundred hour

not t1 - t2 is equal to one by two hour