Aptitude - Problems on Trains - Discussion

Since time is given in seconds , sure you have to convert velocity of train in units of m/sec

Since 1 km = 1000 m
and 1 hr =60 m = 60*60 sec,

According to question,speed 60 km/hr = 60 * (1000/3600) = 50/3 m/sec, time = 9 sec

We know that , distance=speed*time,
therefore length = (50/3)*9 =150 m.

Guys check this out. !

This comment is to make you understand conversion of km/hr to m/s by using easy method. ,

Observe carefully conversion of km/hr to m/s. ,

12*1=12.
12*2=24.
12*3=36.
12*4=48.
12*5=60.

For any number (which has to be converted to m/s from km/hr) coming as the result (r) of multiplication table of 12. , you can easily write it as (quotient*10) /3 m/s. ,

Example:- 60km/hr = 50/3 m/s.

Dear Friends.

The problem is really nice ans soothing. I solved it firstly but when I saw the solution, I confused to see the calculation. After a deep concern and explanation I think it really a nice explanation. Okay friends after that thank to Sundar for posting another problem and solution. Thank to Kartik, Dhessappan, Jain Thomas, Rita, Valimithu, Jayanthi, Vishnu, Poonm, poja, Sunny, Sara and others.

Salary problem
Let's take salary amount as X.
she spends 15% of X on policy=15X/100
55% of X on shopping &house expe=55X/100
rem of salary=12750
so,X-(15X/100)-(55X/100)=12750
30X=1275000
X=42500

We know that
1km=1000meters
1hr=3600seconds
1km/1hr=1000/3600=10/36=5/18m/s
1km/hr=5/18m/s
60km/hr=(60*5/18)

@Divya.

Can you explain the problem which was mentioned by you ?

Can you explain the problem with diagrammatic representation ?

@Bangaru.

If the total salary is 100%, in which 15% spent on insurance policy means 100-15 =85%.

55% spent as expenditure on shopping etc means 85-55 =30%
Savings =salary -expenditure.
30% savings equals to 12,750.

Percentage can be represented as per hundred i.e., 30/100, which is equals to 12,750.

Assume that total salary be X
X *30/100 =12,750
X =12750*100/30
X= 42500.

Let length of the train be 'x' metres...
Speed of the train = 60km/hr(given)
Time = 9seconds(given)

Refer the formulas for train problems...

As the time is given in seconds and answers are given in metre(train length) We are in need to convert from km/hr to m/s
km/hr = 1000m/(60min*60sec) = 5/18 m/s

Length of the train(distance covered a post)= speed * time
= (60*(5/18))*9
= (50/3)*9
= 150 m

For the train related formulas,check the READ MORE in Left corner(Important formulas)...

We know that
1km=1000meters
1hr=3600seconds
1km/1hr=1000/3600=10/36=5/18m/s
1km/hr=5/18m/s
60km/hr=(60*5/18).