INMO 2019 Discussion

This is the place where we may discuss various problems and get updates of INMO 19. I expect the students of different states to post some problems discussed in their INMOTC. I will regularly upload some problems and even practice tests for INMO and expect you to do so too. Hope we all do perform well in INMO and many of us may even get selected for INMO

IN MY NEXT POST, I WILL SEND A MOCK TEST A BIT EASIER THAN INMO, AS IT IS JUST THE BEGINNING.

Note by Maalav Mehta
3 weeks, 4 days ago

No vote yet
1 vote

  Easy Math Editor

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold

- bulleted
- list

  • bulleted
  • list

1. numbered
2. list

  1. numbered
  2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1

paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
    # 4 spaces, and now they show
    # up as a code block.

    print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in \( ... \) or \[ ... \] to ensure proper formatting.
2 \times 3 \( 2 \times 3 \)
2^{34} \( 2^{34} \)
a_{i-1} \( a_{i-1} \)
\frac{2}{3} \( \frac{2}{3} \)
\sqrt{2} \( \sqrt{2} \)
\sum_{i=1}^3 \( \sum_{i=1}^3 \)
\sin \theta \( \sin \theta \)
\boxed{123} \( \boxed{123} \)

Comments

Sort by:

Top Newest

1st Indian National Mathematical Olympiad MOCK 2019 Time: 4 hours Instructions: • Calculators (in any form) and protractors are not allowed. • Rulers and compasses are allowed. • All questions carry equal marks. Maximum marks: 102.

1.A circle passes through the vertex C of a rectangle ABCD and touches its sides AB and AD at M and N respectively If the distance from C to the line segment MN is 5 units, find the area of ABCD.
2.Consider the set {3,5,7,9}. You can choose any 2 numbers a,b and replace them by (4a+3b)/5 and (3a-4b)/5. Prove that you can never get the set {2,3,4,9}.
3.A 3*3 square is said to be a mystic square if i)Its entries are from 1 to 13(both inclusive, repetition allowed) ii)The sum of any row, column or diagonal is always divisible by 13. Find the number of MYSTIC SQUARES.
4.In a triangle ABC, AB=AC and angle A is 20 degrees.D is chosen on AC such that AD=BC.Without using trigonometry, find angle ABD.
5.Let P(x) be a cubic polynomial function with positive coefficients..Prove, if -1≤P(x)≤1 for all x such that -1≤x≤1, prove that sum of coefficients of P(x) is at most 7.
6.Find all functions f:R to R which obey
f((x-y)²)=f(x)²-2xf(y)+f(y)²

Maalav Mehta - 3 weeks, 4 days ago

Log in to reply

Thanks for the mock test!!! What are you focusing on preparing??? Geometry??

Aaghaz Mahajan - 3 weeks, 3 days ago

Log in to reply

I want to improve at geometry, but I hate doing it.

Maalav Mehta - 3 weeks, 3 days ago

Log in to reply

@Maalav Mehta Well, you can start off with some problem solving on AOPS..........BUT, if u want to learn new stuff, the wikis on Brilliant are REALLY good ones...........

Aaghaz Mahajan - 3 weeks, 3 days ago

Log in to reply

@Maalav Mehta Also, if u hate doing it, then focus on something which you like doing and prepare that.......:)

Aaghaz Mahajan - 3 weeks, 3 days ago

Log in to reply

Which state are you from?

Maalav Mehta - 3 weeks, 3 days ago

Log in to reply

@Maalav Mehta I am from Noida..........(UP region).....You???

Aaghaz Mahajan - 3 weeks, 3 days ago

Log in to reply

@Aaghaz Mahajan Gujarat

Maalav Mehta - 3 weeks, 3 days ago

Log in to reply

@Maalav Mehta When is your INMOTC and which teachers are coming?

Maalav Mehta - 3 weeks, 3 days ago

Log in to reply

@Maalav Mehta WHOAH!!!! You have an INMOTC???!!! That is great dude.........yahan pe to aisa kuch inform nhi kara hai!! lol............

Aaghaz Mahajan - 3 weeks, 3 days ago

Log in to reply

@Aaghaz Mahajan You may ask your coordinator to arrange some camp or you may enquire in neighbouring states if they allow outside students

Maalav Mehta - 3 weeks, 2 days ago

Log in to reply

@Maalav Mehta All the best for tomorrow

Maalav Mehta - 2 days, 6 hours ago

Log in to reply

@Maalav Mehta Thanks!!!! Same to you!!

Aaghaz Mahajan - 2 days, 6 hours ago

Log in to reply

Find all functions f:R→R satisfying the equation f(f(x)) + f(x) = 6x

Maalav Mehta - 2 weeks, 5 days ago

Log in to reply

ALL THE BEST FOR TOMORROW GUYS AND GIRLS!!!!!!!!!!!

Maalav Mehta - 2 days, 6 hours ago

Log in to reply

Same to you!!!!

Aaghaz Mahajan - 2 days, 6 hours ago

Log in to reply

How did it go????? How many could you solve????

Aaghaz Mahajan - 1 day, 11 hours ago

Log in to reply

None

Maalav Mehta - 1 day, 9 hours ago

Log in to reply

@Maalav Mehta Really?

Aryan Arya - 1 day, 9 hours ago

Log in to reply

@Aryan Arya Yes

Maalav Mehta - 1 day, 9 hours ago

Log in to reply

@Aryan Arya What do you expect from a class 9 student?

Maalav Mehta - 1 day, 9 hours ago

Log in to reply

How was the inmo?

Aman Pandey - 1 day, 8 hours ago

Log in to reply

Tougher than ever, the fifth question used something called inversion(according to some AOPSers), which has not ever been asked in INMO. Could you solve P6?

Maalav Mehta - 1 day, 8 hours ago

Log in to reply

Yeah problem no 6 looked easy but solving it took me complete hour and mind bending brainstorming and I skipped two or three lemmas and messed everything but solved it. Seems they would care to give 2 or 3 marks.

Aman Pandey - 1 day, 7 hours ago

Log in to reply

@Aman Pandey How did you solve it?

Maalav Mehta - 1 day, 7 hours ago

Log in to reply

@Maalav Mehta No exotic methods just little brainstorming , some examples, inducing them ,predicting the power rule and then proved.😃

Aman Pandey - 1 day, 6 hours ago

Log in to reply

@Aman Pandey Bro, the last question is incorrect and in the solution of Allen faculties, they have found a counter example

Maalav Mehta - 13 hours ago

Log in to reply

@Maalav Mehta Yes me too saw today my answer is as not Allen's solution buy I used the continuity of the function too. So seems wrong now.

Aman Pandey - 7 hours ago

Log in to reply

@Aman Pandey The power rule assumed by me was wrong as I thought only about rational numbers didn't seek for irrational ones.

Aman Pandey - 7 hours ago

Log in to reply

Do you think that the cut off may be lower this time since as per my experience this year, the paper was relatively tougher

Shubhraneel Pal - 1 day, 8 hours ago

Log in to reply

Yes, the cutoff will be around 35-40

Maalav Mehta - 1 day, 8 hours ago

Log in to reply

Hey everyone. I appeared for INMO 2019 and solved P2 and P3. In P6, I managed to provide a "pseudo-proof" that f(x,y) =1. What are my chances of selection? Also, I couldn't solve P1 but I heard many saying that it was the easiest problem. Is this really the case?

Vibhav Aggarwal - 12 hours ago

Log in to reply

Hey dude........same case over here...........I mean even I have done the EXACT same things except P6, in which I was only able to prove the first part..........Oh well.......Chances are slim...........And Yes, P1 was the easiest......IDK why it did not strike me during the exam........!!!!

Aaghaz Mahajan - 11 hours ago

Log in to reply

Can you provide a hint for P1?

Vibhav Aggarwal - 11 hours ago

Log in to reply

@Vibhav Aggarwal Well, Allen has already posted their solutions, but my method was using a lot of trigonometry...........You know, Sine rule and Cosine rule........and that took me too long.....

Aaghaz Mahajan - 11 hours ago

Log in to reply

Btw, which class are you in?? And from which state??

Aaghaz Mahajan - 11 hours ago

Log in to reply

I am in 12th class from Rajasthan state. What about you?

Vibhav Aggarwal - 11 hours ago

Log in to reply

@Vibhav Aggarwal Ohhh I am in class 11th.......Uttar Pradesh........

Aaghaz Mahajan - 11 hours ago

Log in to reply

@Vibhav Aggarwal So, you are giving JEE???

Aaghaz Mahajan - 11 hours ago

Log in to reply

@Aaghaz Mahajan Yep

Vibhav Aggarwal - 11 hours ago

Log in to reply

Did you hear that P6 was wrong? What would be impact. Will it be deleted or there could be a reexam??

Suchir Kaustav - 8 hours ago

Log in to reply

Check it on aops

Maalav Mehta - 8 hours ago

Log in to reply

@Maalav Mehta What do u think? HBCSE will delete the qn?

Suchir Kaustav - 8 hours ago

Log in to reply

@Suchir Kaustav Probably, but that is not correct as many would have spent hours on the question without knowing that it is incorrect

Maalav Mehta - 7 hours ago

Log in to reply

@Maalav Mehta What could be the cut off? I guess, it should be around 40-45.

Suchir Kaustav - 7 hours ago

Log in to reply

For p2 I did not use php but some approach that is explicitly not php but just the same thing as that. How much do I expect?

Shubhraneel Pal - 7 hours ago

Log in to reply

If it is mathematically correct, you get full

Maalav Mehta - 7 hours ago

Log in to reply

@Suchir Kaustav @Maalav Mehta Is this the first time this has happened that a question in inmo came wrong? If this did happen before then what was done? Any idea?

Shubhraneel Pal - 7 hours ago

Log in to reply

I remember it happened in 1999 and 2011. But no idea what was done

Maalav Mehta - 7 hours ago

Log in to reply

Reexam is a huge logistical challenge on the part of HBCSE. I think they should increase the number of selections.

Suchir Kaustav - 7 hours ago

Log in to reply

If the ans is wrong and the approach is correct or vice versa how much can one expect??

Aryan Arya - 1 day, 8 hours ago

Log in to reply

If the approach is more than 70 percent correct, you may expect 12 marks. If the answer is correct but obtained by doing some nonsensical stuff, then you may get 2 or 3 marks

Maalav Mehta - 1 day, 8 hours ago

Log in to reply

Hey what can be expected cutoff this year??

Aryan Arya - 1 day, 10 hours ago

Log in to reply

RMO coordinator of Gujarat told that according to trend, you are required to solve 3-4 questions

Maalav Mehta - 1 day, 9 hours ago

Log in to reply

This time I guess cutoff will be around 40

Maalav Mehta - 1 day, 8 hours ago

Log in to reply

What about cut off for merit certificate?

Suchir Kaustav - 8 hours ago

Log in to reply

×

Problem Loading...

Note Loading...

Set Loading...