Question

A journey cover in 3 hour with a speed of 90 km per hour for the same journey what will speed of Same journey for in 5 hr.​

Answer 1

Answer

Correct option is

A

45

Let original speed =xkm/hr

⇒  Time taken to travel =x90hr

⇒  New speed =(x+15)km/hr

⇒  Time taken to travel =x+1590hr

∴  x90=x+1590+21

⇒  x90−x+1590=21

⇒  90(x1−x+151)=21

⇒  x(x+15)x+15−x=1801

⇒  15×180=x(x+15)

⇒  2700=x2+15x

Answer 2

Answer:

Car:- speed=60 kmph

Time=15 hrs

Distance=speed× time

=15×60=900 km

For the train to travel same distance

distance=900 km

speed=90 kmph

Time=

speed

distance

=

90

900

=10 hours

plz tick your brain list plz.