Aptitude - Problems on Trains - Discussion

hai!frinds,.
in this above problem they given speed of the one object.
we know that if the two objectives are move in the same direction then the formula is"(A-B)"(assume A is one objective and B is another objective).so,nw we know one objective speed(taken as B speed we know),that is subtutited in above.

then s=(A-5).(here it is the speed of the train)
1.in the problem train(objective) speed is given in the form of seconds,so convert the seconds into the km/hr.because of the one objective speed is give in the form of km/hr and also answer is given in the form of km/hr.
2.while the conversion we have to follow the following,
i)if we covert m/sec inti km/hr then multiplis with"8/15"
ii)if we convert km/hr into the m/sec then multiplies with "15/8"
3.we know the formula for speed is
"speed=Distance/Time"(s=D/T)
s=125/10 m/sec [here 125 is the distance,and 10 is the speed of the objective]
the conversion
s=125/10*(18/5)km/hr
=45.
4.in starting we initialse the speed(s)=A-5
then subtuted that speed in the above,
A-5=45
A=50.
therefore the speed of the train(another objective) is "A=50".

Hi Friend's
Thanks for teaching it really works dude ,
1km=1000m and 1hr =36000 then 5/18 m/sec it's simple.

Thanks for that .........!

Hi friend's
Hey ravi nice explanation.

@ all apply logic don't simply go for routine

speed of man is 5km/hr and in mt/sec is 1.39.
so total distance covered by main in 10 sec is 13.9 m
so total distance covered by train in 10 sec is 125+13.9=138.9
so total distance covered by train in 1 sec is 13.89m
and if we convert this in km/hr
i.e. 13.89*3600/1000= 50km/hr

Thanks Amit

Train moves with speed 125m/10 sec,.. So need to convert it as KM/ Hr ,..To convert 125m to KM we have to divide it with 1000 so it is 125/1000 and to convert 10 sec to hrs we have to divide it with 3600 so it is 10/3600.
Then it becomes (125/1000)Km/(10/3600)hr.
So we can change it to (125/1000)*(3600/10)..
It is (5/40)*(360) = (360*5)/40 = 180/4 = 45 Km/Hr.

.. Now we have got the speed in 1 Hour ie 45 Km..

As the man is travelling at 5 Km/Hr.. In that 1 Hr he already travelled 5 Km's.. So the train speed should be 45+5 Km's to cross that person in that 1 Hr.. Now answer is 50 Km/Hr.. I hope it is clear,... Take a paper a write exactly what i have given above,.. I am sure u guys will like it..

Can anyone find another way of solving this? Apart from relative speed?

How to relative 45 with man running speed. Please explain it any one.

This is good Question i understand that, some friend disturb for 18/5. its simple its unit for km/hr. let see that1km=1000m & 1hr = 3600 second so 1000/3600 = 5/18 . And see that If we want to small unit convert in to big unit we have to divide & if we want to big unit convert in to small we have to multiply so here they dividing and write 18/5 ok so encourage your self my friend go ahead. VIMAL SONI & DUSHYANT SONI

@Vasudeva reddy

1km = 1000m =100,000cm
1 inch = 2.54cm
1 ft=12 inches = (12*2.54)cm
1km = 0.621371192 mile
1.609344 km = 1 mile