Question

10. An aeroplane covers 200 mts in one sec. After covering
2/3
part of its journey, the
plane is slows down by 25% and it reaches its destination in the next 10 mins. What km
did the plane covered?​

Answer 1

$here \: is \: ur \: answer$

Let the usual time taken by the aeroplane =x hr.

Distance =1500km

In first case-

speed= x1500 km/h ………..(1)

In second case-

time taken by aeroplane=x− 21

hr

∴ Speed= x− 21 1500 km/h ………(2)

Increased speed=250 km/h

So,

x− 1

1500 − x1500

=2501

1500 × 2x−1 − x1500

=250

2x−1

3000 − x1500

=250

(2x−1)x

3000x−3000x+1500

=250

2x 2

−x1500

=250

6=2x 2

−x2x 2

−x=6 2x 2

−x−6=02x 2

−4x+3x−6=0

2x(x−2)+3(x−2)=0

(x−2)(2x+3)=0

x=2,x= 2−3

So time can not be negative

x=2

then speed= x− 21

1500 = 2− 21

1500

=1000 km/h.