Question

The distance between two points A and B is 110 km. A motorcyclist starts from A towards B at 7 am at the speed of 20km/hr.Another motorcyclist starts from B towards A at 8 am at a speed of 25km/hr.When will they cross each other? ​

Answer 1

The distance from A to B =110=110km.

The biker from A starts at 7am7am.

So by 8 am he travels for 1 hr1hr.

His speed =20 km/hr=20km/hr.

Then the distance covered form 7am7am to 8am = 20km8am=20km.

Rest of the distance =(110-20)km=90=(110−20)km=90km.

Now the biker from B starts.

Their relative speed =(20+25)km/hr.=45=(20+25)km/hr.=45km/hr.

(since they are approaching each other.)

So, the time taken=\dfrac { distance }{ relative\quad speed } =\dfrac { 90 }{ 45 }  

relativespeed

distance

​  

=  

45

90

​  

hrs.=2hrs.

So they will meet each other after 33 hrs from7am7am

i.e at 10am10am.

Answer 2

Answer:

ANSWER IS 3 HOURS