Showing posts with label JMO. Show all posts
Showing posts with label JMO. Show all posts

Monday, February 8, 2016

Puzzle

There are a 1000 locks in closed position. 1000 children numbering 1 to 1000 approach the lock one by one. The rule is the child (say with number 'n') can open or close the lock numbering  in multiples of "n" only.
so the child in number one position can open all the locks. Child number 2 will be able to close all the locks in multiples of 2 (like 2, 4, 6 .... upto 1000). The other locks will remain as they are.
After all the 1000 children have had their chance, how many locks will be in open position.

geometry

 
















I would appreciate receiving your solutions.

Friday, December 11, 2015

geometry - triangle

A triangle has a perimeter of 36 cm. The altitudes of the triangles are in the ratio of 1:2:3. Find the measure of each sides.



Friday, July 17, 2015

Teaser on area

ABCD is a rectangle. The area of shaded region is 15 cm2. find the area of rectangle ABCD





Monday, July 13, 2015

Another Teaser on Area

Find the Area of rectangle ABCD
given area of triangle AOC = 40 m2
and area of triangle BOD = 30% of area of Rectangle ABCD


Teaser on Area

Find the Area of rectangle ABCD
given area of triangle AOC = 60 m2
and area of triangle AOB = 40% of area of Rectangle ABCD





Friday, July 10, 2015

scratch your brains guys....this is interesting

Nanu's Grandfather's age is a 2 digit number and her father's age is reverse of her grandfather's age. Nanu's age is 4 times the difference in age between her grandfather and her father. What is Nanu's age.

answer 9 years

Thursday, June 25, 2015

Coordinate Geometry - Singapore Maths Olympiad

Let A and B be points that lie on the parabola y = x2 such that both are at a distance of 8√2 units from the line y = -x – 4. Find the square of distance between A and B

Geometry

Given an equilateral triangle, what is the ratio of the area of circumscribed circle to the are of its inscribed circle?

Sets and Relations - Singapore Maths Olympiad

Suppose that a function M(n), where n is a +ve integer, is defined by
M(n) = n - 10 for n > 100
M(n) = M(M(n +11) for n ≤ 100
How many solutions does the equation M(n) = 91 have?

Saturday, June 20, 2015

Singapore maths Olympiad

Let a,b,c,d be real numbers such that a2 + b2 + 2a – 4b + 4 = 0 and c2 + d2 – 4c + 4d + 4 = 0.

Let m and M be minimum and Maximum value of (a – c)2 + (b – d)2 respectively. What is m x M.

Singapore maths olympiad, number

If a1, a2, a3, .............. a2011 are positive integers such that (a1 + a2 + .....a2011) = a1.a2.....a2011

Then find the max value of (a1 + a2 + .....a2011)

Singapore maths Olympiad

Find the largest positive integer ‘n’ such that (n + 10) is a divisor of n3 + 2011

Singapore maths Olympiad, Numbers

Let 'n' be the smallest positive integer such that the sum of its digits is 2011. how many digits does 'n' have?

Probability, Singapore Maths Olympiad

A fair dice is thrown 3 times. the results of the first, second and the third throw are recorded as x, y and z respectively. Suppose x + y = z. What is the probability that one of x,y,z is atleast 2?

Singapore Maths Olympiad

Singapore Maths Olympiad