# IMO (Olympiad) preparation : Do’s and Dont’s

Before getting into how to prepare for IMO (International Mathematics Olympiad), conducted by SOF World, let’s find how it is different from the conventional Math exams. Though it follows same curriculum, questions asked in this have certain characteristics which differentiate it from normal exams.

### IMO question pattern

In addition to regular questions, Olympiad also have several questions of following type

1. Mixing of skills
2. Higher grade questions (which can be solved by extending the concepts learned in current grade)
3. Questions intentionally created to cause confusion

#### 1. Mixing of skills

Let’s look at this question,

Tap A, which has a circular opening of 1 cm radius, fills a tank in 40 minute. There is another tap which has an circular opening of 2 cm radius. If both taps are opened together find the time taken to fill the tank.

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Now, this question seems hard for a middle grade student, but if you observe carefully this question has following parts.

Part 1: You need to find the time taken by second tap to fill the tank. Once you know the individual time taken by both the taps you know how to find the time taken by both taps to fill the tank.

Part 2: You know that amount of water filled by tap is proportional to the cross section area of the tap. As you know the area of circle = πR2 , therefore area of second tap will be four times the are of first tap. Hence, second tap will fill the tank in 40/4 = 10 minutes.

Part 3 : Now you know how to find the time to fill tank with both taps which individually takes 40 and 10 minutes respectively.

So this questions is testing two skills in one question.

Skill 1 : Area of circle

Skill 2 : Inverse proportion.

So, what should students do

• Practice different types of questions at home
• When you see questions which looks familiar in parts, try to break them using the skills familiar to you.

Though IMO questions are in synchronization with NCERT, they do tend to ask questions on the same topic but of a complexity of higher grades (Though you can still solve them using the concepts taught in current grade).

Let’s look at this question

Find the area of this shape,

Let’s say that this question is asked in a grade, where you are taught only the area of rectangles and not the area of such complex shapes.

But if you think (or have seen such questions during practice), you can easily solve this using the concept of rectangle’s area only, as above picture consists of a triangle and a rectangle. Area of triangle (though not taught), can still be computed using the fact that the area of this triangle will be half of the enclosing rectangle (a rectangle of size (18-6) x 5).

So the point is that even if the skill used in the question looks unknown, you can still solve it using a “known skill + common sense”. Of-course it is easier said than done. For that it is important to practice as many questions as you can.

#### 3. Questions intentionally created to cause confusion

Let’s looks at this question.

Sulekha has 8 pair of red socks and 8 pair of brown socks. All the socks are in a bag, if Sulekha picks the socks without looking at them, how many socks she has to remove from the bag before she can be sure that she has a pair of a single color ?

This is a very simple question, but kids have a tendency to think that in order to find answer, all the numbers given in question need to be used somehow (It may sounds odd but studies show that this is true).

The answer to the above question is three, because in three socks you are guaranteed to have two socks of same color. But many kids answer as 17. So the point here is to remain focused on the question and not to get confused.

### What do do?

So we saw that the Olympiad questions could be complex, requires higher-order thinking etc. But what exactly kids need to do to perform better in these exams? Here are some suggestions,

#### Before exam

1. Identify all the skills required for a topic and make sure you have understood all of them. (e.g. some example skills required to master Quadratic equations are, solve quadratic equations using factorization, Dharacharya method, conditions for unique/real solution to exist, representing real life problems using Quadratic equation, application in word problems etc.).
2. Make sure you understand the concept behind each and every skill. Use theory provided in the NCERT books, if any doubt consult with your teacher or you can also ask experts in some online forum (e.g. Q&A).
3. Practice as much as you can. Since regular books do not provide variety of question, you can consider using some online resource (e.g. edugain.com) to practice more variety of questions.

#### During exam

1. Do not panic and read the complete question carefully. This is most important point for an exam like Olympiad where questions are intentionally created to cause confusion. It is fine to spend some extra seconds to understand the question, rather than doing it incorrectly and again spending extra time, when your answer does not matches any of the given choices.
2. If question seems tough, try to break the problems into parts.
3. However hard the question might look, it is almost sure that all the skills used in the question are taught you in your class. You just need to identify and apply the correct skill.
4. Sometimes, you may have to apply combination of skills. Sometime you may have to extend the concepts learned in your current grade.

#### After exam

1. Relax and stop worrying about how you performed.
2. Don’t think too much about the silly mistakes that you might have made. Everyone make them so no need to loose your sleep over it.
3. Take break for couple of days, and start preparing for next year exam. Remember practice is the key, so practice as much as you can.

Online resources for Olympiad questions practice