Problems on Train_Lesson-3(Two Trains Meeting)

#feelfreetolearn

[chanduuppalapati]

Normal method

<
->60 40<-
after one hour 40 kms decreased
now then distance will be

0 520
from 7 o clock two trains meet at same time, wkt s=d/t
d1/s1=d2/s2
let us consider they meet at x from chennai and 520-x from mumbai
x/60=520-x/40
2x=3(520)-3x
5x=3(520)
x=312
from Mumbai 560-312=248
now time
s=d/t
when two trains travelling in opposite direction, speed =40+60=100.
t=d/s
t=520/100
t=5.2 hrs
time will be 5.2 + 1, bcz at 6 am from mumbai started.=6.2hrs
we can convert from decimal to time by
0.2 *60=12
so 6hrs 12min
so answer will be from 7 o clock, 6+6h 12 min=12.12 min

[monameemaity]

LAST PROBLEM ""NORMAL METHOD WITH EXPLANATION .""
Train 1-
5 am (time )
Speed - 60 km /hr
So 1 hr it travels 60 km
30 mins it travels 30 km
Therefore - it started at 5 am and traveled 90 km when it was 6:30 am . at 6 :30 am the TRAIN 2 is at station and its going in the direction of TRAIN 1 and they r both in the same time zone "6:30" . now the problem is like the policeman chasing thief and when he will catch the thief .
Time 6: 30 am :
Distance between TRAIN 1 and TRAIN 2 is = 90 km
Let TRAIN 1 travel "x" distance before TRAIN 2 and TRAIN 1 meet
So
(X+ 90)/75=X/60
Because their meeting time is same
X= 360
So distance from station where they meet is
360+90=450
Time is X/60=360/60=6 hr
These all started when we started the sum by bringing both trains in same time zone ie "6:30am " soo we need to add 6 hr to 6 :30 am which is 12:30 pm in the noon

[ashokseetharam]

Normal method for 4 is simple

Time difference is 1 hr so in 1 hr train a complete 40km, then the total distance will be 560-40= 520, ,

Now the equation is x/40 =520-x/60,
X=208
Distance from mumbai is 208+40 =248...,


5th question also same related to this concept.... Tq

[saikumarbolamwar]

Que:4:- Train1 speed is 40km/hr. So till 7 am it will cover 40km dist. And after applying time equating method(x/40=(520-x)/60) on remaining dist. i.e(560-40=520km) we will get the value of x=208. So the total dist covered by Train1 from 6.00am will be 40km+208km=248km. To find time divide it by Train1 speed(40km/hr) you will get 6hr 20min. So from given time will be 6.00am +6hr 20min---> 12.20pm.
Thank you😉

[vishalsinghsengar]

The NORMAL METHOD,
People who are getting answer as 224 they are wrong because this not exactly solved as question 3 solved by sir. Please read the question ones before read my answer further

First train from Mumbai travelled for an hour, when the second train from Chennai has started...
So subtract that distance, that is 40km(since speed of train from mumbai is 40kmph) from total distance 560km.
Now consider, there is only 520km between the two stations.
As we know that, when the trains are traveling in the opposite direction, we have to add their speed. That is, 40 + 60 = 100. So, the distance covered by two trains together in 1 hour is 100km.

The total distance is 520km(excluding the 40km). 520/100 = 5.2 (in decimal)
That is, they take 5hrs 12mins(in mins) to meet each other.. (starting from 7am). So, adding 5hrs 12mins to 7am gives 12:12pm.

Coming to the distance, it was asked from Mumbai. So consider first train speed. 40kmph. This train travelled for 6hrs 12mins(including the 1hr it took before the other train has started) to meet another train. So, 40 * 6.2(decimal value is used for normal calculations) = 248km.

Finally, the time where the two trains met is 12:12pm, and the distance from Mumbai is 248km.


Credit @Priyanka M

[blackpearl-ydiy]

train 1 starts @ 5:00 am and train 2 @ 6:30 am... initialize them to be on the same time...so time difference is 1hr 30 min.. train 1 will cover 90 km for 1.5 hrs..
then u need to solve the equation:
X /75 = X+90 / 60
on solving u ll get X=450 km
and time 450/75= 6 hrs..
since the distance has been calculated from 6:30 pm u need to add 6+6:30 nd u ll get 12:30 pm is the time where they meet

[kirubababu]

In last problem, ( type3)
At 6.30, the distance between two trains is 90kms,
After every hour distance between two trains is reduced by 15kms (75-60)
So to reduce the distance 90kms, it takes 6hours.

Distance cover = time * speed
D= 7.5hours * 60 = 450kms
Or
D = 6* 75 = 450kms

[abhishekguleria]

Sir, with all respect, need lessons on Boats and Streams. Will be really helpful sir. Thank you!!

[udayanair]

It's true that you upload videos after taking some time but each videos comes with ultimate solutions . Really so thankful to you

[syamilyanandukrishna]

24:37 - I think 6.2hours is 6 hours 12 mins. Not 6 hrs 20 min.

Kindly upload normal method for type 1 questions

[dineshprakash]

For 5th, a normal method like chasing problem

First, train A start it's a journey at 5 a.m. at 60km/hr then train B starts it's a journey at 6.30 am at 75km/hr so, time different is 1.30 hours

Therefore, train A travel for 1.30 hours is 90km
Then apply chasing formula
D=∆D(a/(a~b))
=90(75/15)
D=450km

T=D/S
=450/75

[Vishnureddy]

By 6:30Am train A already travelled 90km
At 6:30Am train B at the starting point itself
B———90km———A———x————?
Both will meet at same time so equate both time T=D/S
Train B needs to cover 90+x distance, train A will cover x distance before both meets
So 90+x/75=x/60————> x=360km
Total distance covered by B=360+90=450km
Time=450/75=6hrs
Total time=6:30+6=12:30Pm

[naveentiwari]

sir i think 4th question answer is wrong "the time at witch 1st train time is 12:12 noon"....
because 6.20 hours means 6 hours and 12 min .
like that = "6.20 hours = 6 hours+0.2 min =12 min,
so total 6 hours 12 min

[subbus-g]

10:23 another way...ratio of speeds of A & B 36:42 which is 6:7 .since time is constant of distances covered by A and distance covered by B is 6:7
let the distances be 6x, 7x respectively .given that difference btw the distances covered is 48km ie
now distance btw them initially is 7x+6x=13x=13*48=624

[saiprasannakumar]

Good Concepts with the Superb explanation..., #Tanqq very much

[changechan]

In 4th sum time 6hr 12minuts, two trains meet at 12:12 PM

[balanagachari]

Your explanation is awesome sir, even arts students also can easily learn all these things very well. Thank you very much sir.

[jeldiprasanthi]

your videos excellent sir ever seen this type of teaching

[pdsaiprasad]

15:52 Traditional method :
Train T1 travels 40 km/hr means per hour T1 cover 40km and it starts at 6:00 am
Train T2 travels 60 km/hr covers 60 Km per hour and starts at 7:00am
here we have to set time constantly so, I add 1hr to the train T1 dis --> 40+40 =80 km/hr {speed of 1st train T1}
Then both trains starts at same time which 7:00 am
now equating
T1=T2
D1/S1 =D2/S2 ( let us take T2 cover x km then T1 covers (560 -- x) )
(560 -- x) / 80 = x / 60 (here T1 speed=80km/hr, so it covers more distance as compared to T2)
x = 240 km ( Meeting point )

[sindhumanjappa]

Your teaching is just amazing thank you soo much sir😊👍