Question

in a flight of 2800 kilometre and aircraft was slow down due to bad weather its average speed is reduced by Undertaker and time increased by 30 minutes find the duration of flight​

Answer 1

Answer:

speed of aircraft= x

Distance = 2800 km

Time = Distance / Speed = 2800/x 

Given:

The speed has reduced by 100 and time is reduced by 30 min

New speed = (x – 100)

That is, 30 min = 30/60 hr = (1/2) hr 

Time taken= 2800/(x – 100) hr

=2800/(x – 100)

= (2800/x) + (1/2)

2800/(x-100) -` (2800/x)  =  1/2

x² - 100x - 560000  = 0

x² - 800x + 700x - 560000  =  0

x(x - 800) + 700(x - 800)  =  0

(x + 700) (x - 800)  =  0

SO,

x  =  - 700 or 800

Thus original duration of the flight =  2800/800 = 7/2 hours

OR = 3 hr 30 mins