Problems on trains play a major role quantitative aptitude test. There is no competitive exam without the questions from this topic. We have already learned this topic in our lower classes.Even though we have already been taught this topic in our lower classes, we need to learn some more short cuts which are being used to solve the problems in the above topic.
The only thing we have to do is, we need to apply the appropriate short cut and solve the problems in a limited time. This limited time will be one minute or less than one minute in most of the competitive exams.
Points to remember
|1.To convert km/hr in to m/sec, we need to multiply the given value by 5/18.|
|2.To convert m/sec in to km/hr, we need to multiply the given value by 18/5.|
|3.If the length of the train is "l"meters, time taken by the train to pass a standing man or a pole or a signal is equal to the time taken by the train to cover "l" meters.|
|4.If the length of the train is "l"meters, time taken by the train to pass an object of length "a" meters is time taken by the train to cover (l+a) meters.|
|5. If two trains are moving on the same directions with speed of "p" m/sec and "q" m/sec (here p > q), then their relative speed is (p-q)m/sec.|
|6.If two trains are moving opposite to each other in different tracks with speed of "p" m/sec and "q" m/sec, then their relative speed is (p+q)m/sec.|
|7.Let "a" and "b" are the lengths of the two trains.They are traveling on the same direction with the speed "p" m/sec and "q" m/sec(here p > q),then the time taken by the faster train to cross the slower train = (a+b)/(p-q) seconds.|
|8. Let "a" and "b" are the lengths of the two trains.They are traveling opposite to each other in different tracks with the speed "p" m/sec and "q" m/sec,then the time taken by the trains to cross each other = (a+b)/(p+q) seconds.|
|9.Two trains leave at the same time from the stations P and Q and moving towards each other.After crossing, they take "p" hours and "q" hours to reach Q and P respectively.Then the ratio of the speeds of two trains is square root (q) : square root (p)|
Students who are preparing to improve their aptitude skills and those who are preparing for this type of competitive test must prepare this topic in order to have better score. Because, today there is no competitive exam without questions from the topic problems on trains. Whether a person is going to write placement exam to get placed or a student is going to write a competitive exam in order to get admission in university, they must be prepared to solve problems on trains. This is the reason for why people must study this topic.
As we mentioned in the above paragraph, a person who wants to get placed in a company and a students who wants to get admission in university for higher studies must write competitive exams like placement test and entrance exam. To meet the above requirement, it is very important to score more marks in the above mentioned competitive exams. To score more marks, they have to prepare the problems on trains. Preparing this topic would definitely improve their marks in the above exams. Preparing this topic is not difficult task. We are just going to remember the stuff that we have already learned in our lower classes
Students have to learn few basic operations in this topic time and work and some additional tricks. Already we are much clear with the four basic operations which we often use in math. They are addition, subtraction, multiplication and division. Even though we are much clear with these four basic operations, we have to be knowing some more stuff to do the problems which are being asked from this topic in competitive exams. The stuff which I have mentioned above is nothing but the tricks and shortcuts which need to solve the problems in a very short time.
Short cut is nothing but the easiest way to solve problems related to trains. In competitive exams, we will have very limited time to solve each problem. Then only we will be able to attend all the questions. If we do problems in competitive exams in perfect manner with all the steps, it will definitely take much time and we may not able to attend the other questions. So we need some other way in which the problems can be solved in a very short time. The way we need to solve the problem quickly is called as shortcut.
Here, we are going to have some problems on trains . You can check your answer online and see step by step solution.
1. It takes 20 seconds for a train running at 54 kmph to cross a platform.And it takes 12 seconds for the same train in the same speed to cross a man walking at the rate of 6 kmph in the same direction in which the train is running. What is the length of the train and length of platform (in meters).