Saturday, October 25, 2014

continued fraction

                                                                                                                                           



   




number, division --- JMO

 











numbers / Division - JMO


Wednesday, October 22, 2014

JMO questions STD V / STD VI

1.       You are given that 47658 x 39876 = 1900410408. Without directly multiplying, use the given information to solve the following question:
52.342 x 0.60124
2.       Find the value of 19999 x 299999 using the information 19999 = 20000 – 1 and 299999 = 300000 – 1.
3.       Consider the number 12345.....11121314........566. Find the 500th digit.
                                                                                                                                  
Find 4 fractions which lie between 2/3 and 3/4  such that they divide the fractions in 5 equal parts.                           

information

https://sites.google.com/site/tripuramathematicalsociety/olympiad

This site carries a lot of information on reference books for Olympiad.

Wednesday, October 8, 2014

series

fill in the next numbers:
2, 7, 10, 22, 18, 37, 26,........


pipes and cistern

A leak in the bottom of a tank can empty the full tank in 6 hours. An inlet pipe fills water at the rate of 4 liters a minute. When the tank is full, the inlet is opened and due to the leak, the tank is empty in 24 hours. How many liters does the cistern hold?


pipes and cisterns

Three pipes A, B and C can fill a tank in 6 hours. All the three pipes are kept open for 2 hours, C is then closed and A and B fills the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is ................


pipes and cisterns

A tank is filled in 10 hours by three pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe A alone take to fill the tank?

pipes and cisterns

Three pipes A, B and C can fill up a tank from empty to full in 10 minutes, 20 minutes, and 30 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P,Q and R respectively. What is the proportion of the solution P in the liquid in the tank after 6 minutes?


numbers, JMO



If x ε N in f(x) = 6x + 1 and g(x) = 6x – 1. Then the Venn diagram representation for f(x), g(x) and prime numbers P is given by:

  
















Sunday, October 5, 2014

JMO

How to construct a 3 x 3 or 5 x 5 or 7 x 7 magic square



Magic square



This is a nice video on Magic square. Do not forget to click on the link that appears at the end of the video. That tells you how to construct a magic square 

Magic square


This is a nice tutorial on Magic Square

http://mathforum.org/alejandre/magic.square/adler/adler4.html

JMO - number of ways

If you can travel from Mumbai to Baroda by 6 trains, from Baroda to Jaipur by 4 trains and from Jaipur to Delhi by 3 Trains. Then in how many ways can you travel from Mumbai to Delhi?


Saturday, October 4, 2014

numbers

Did you know that for 76 raised to the power of n, where n is an element of Natural numbers, the last 2 digits is always 76!

761 = 76
762 = 5776
763 = 438976
764 = 33362176
765 = 2535525376 

Friday, October 3, 2014

number

Read the pattern:
666 x 666 = 443556
6666 x 6666 = 44435556
66666 x 66666 = 4444355556

numbers

show that the square of any prime number reduced by one is always divisible by 24.


division

A three digit number is entered twice into the calculator. What will be the Remainder when the number in the calculator is divided by 91.


division

If a number is successively divided by 9,11,13 then it leaves a Remainder of 8,9 and 8 respectively.

Find the smallest number that satisfies this condition.

factors

For the number 610 x 717 x 5527, find
1.       The number of prime factors
2.       The number of all the factors.

tutorials -sum of factors

Sum of Factors

If a number N can be expressed as product of prime factors such that
N = pa x qb x rc...............................

Write the power of each of the prime factors beginning with zero and going to thee highest power of the prime number.
Record the same for each prime number.

An example will help
64= 26
Then the sum of factors (20 + 21 + 22 + 23 + 24 + 25 + 26) = 1 + 2 + 4 + 8 + 16 + 32 + 64 =  127


Another Example:
Find the total number of factors of 222.
222 = 2 x 3 x 37
Or, 222 = 21 x 31 x 371
then the sum of factors are (20 + 21) (30 + 31) (370 + 371) = (1+2)(1+3)(1+37) = 3 x 4 x 38 = 456

We will check the answer
The factors of 222 are 1, 2, 3, 6, 37, 74, 111, 222.
Sum of factors = 456

division

When we divide 333435 by 34 the remainder is a and when we divide 333534 by 34 the remainder is b. What is the value of b – a?


tutorial on number of factors

To find the number of factors of a number
If a number N can be expressed as product of prime factors such that
N = pa x qb x rc...............................
Then, the total number of factors including N and 1 is given by
(a + 1)x(b + 1)x(c + 1).................................

Example:
Find the total number of factors of 222.
222 = 2 x 3 x 37
Or, 222 = 21 x 31 x 371
So, the total number of factors = (1+1)x(1+1)x(1+1) = 2x2x2 = 8
We can check the answer as shown below.
The factors of 222 are 1, 2, 3, 6, 37, 74, 111, 222.


Find the total number of factors of 64.
64 = 26
So, the total number of factors = (6+1) = 7
We can check the answer as shown below.
The factors of 64 are 1, 2, 4, 8, 16, 32, 64.

Monday, September 29, 2014

JMO division



If 8n is divided by 6, then for n € N, & n is odd, and for n € N,& n is even what is the Remainder?

JMO



If 2356 is divided by 11 what is the Remainder?

Saturday, September 27, 2014

Average

There are three numbers, the average of first two numbers is 2 and the average of the last two numbers is 3, and the average of the first and the last numbers is 4. What is the average of three numbers?


JMO - DIVISION

Which is the largest number that will perfectly divide 1011001 
a) 10000
b) 1000
c) 100
d) 100001


JMO - numbers

How many twin prime numbers are there between 1 and 100?
Twin prime numbers are prime numbers which differ from each other by 2.


JMO Division

When a + b is divided by 12, the Remainder is 8. When a - b is divided by 12 the Remainder is 6. If a > b, then find the Remainder when ab is divided by 6?

JMO --- numbers

We have a four-digit number that is a multiple of 9. Of the four digits, three of the consecutive digits are same. How many such numbers are possible?

JMO numbers

Between 1 to 10,000, how many times does the digit 7 appear?


JMO - Division

If S = 123456789101112................9979989991000

What will be the Remainder when S is divided by 9.


JMO - division

If P =1234567891011.............9989991000

find the Remainder when the first 1000 digits are divided by 16.


JMO - number

If P =1234567891011.............9989991000

Find the 1000th digit from the left

Friday, September 26, 2014

Tutorial

Two prime numbers A,(A<B) are called twin primes if they differ by 2.
Also, any prime number greater than 3 will be in the form of 6x+1 or 6x1.

Eg. of twin prime
5,7
11,13
17,19
29,31

eg. of prime numbers with 6x + 1
7,13, 19, 31, 37, 43, 61.......
eg. of prime numbers with 6x - 1
5, 11, 17, 23, 29, 41.......

JMO - division

What is the Remainder when 231 is divided by 5?


JMO - division

When a certain number is divided by 222, it leaves a remainder of 35, another number when divided by 407 leaves a remainder 47. What is the remainder when the sum of these two numbers is divided by 37?


JMO --- numbers

Find the value of M and N respectively if M39048458N is divisible by 8 and 11, where M and N are single digit integers?

JMO - division


Find the remainder when 7187 is divided by 800.

JMO



What is the Remainder in  75 ÷ 6

JMO



What is the difference between the units place in (461461 - 456456) ?

JMO


With the 5 digits 3,4,5,6 and 7, how many possible numbers can be formed which is divisible by 11.


JMO, numbers

In the number 259260261262263....490491492. How many 8's are there?

numbers, JMO

Nanu wrote all the numbers from 200 to 300. Then she started counting the number of two's that has been used while writing all these numbers. What is the number that she will get?


JMO, numbers

How many keystrokes are needed to type numbers from 1 to 2000 on a standard keyboard?

JMO

For what value of 'n' will the remainder of 351n and 352n be the same when divided by 7?


Thursday, September 25, 2014

JMO


Suppose n is an integer such that the sum of digits on n is 2, and 1010<n<1011. The number of different values of n is:

JMO

The least common multiple of two natural numbers a and b, is 399. What is the minimum possible sum of the digits of the number a(given a > b)?


JMO

What is the unit's digit of the number 62564256

JMO

What is the remainder when 91+92+93+....+98 is divided by 6?


JMO

Find the remainder when 3164 is divided by 162


JMO

How many natural numbers below 860 are divisible by 5 and 11 but not by 3


Tuesday, September 23, 2014

division

A number when divided by a divisor leaves a remainder of 24. When twice the original number is divided by the same divisor, the remainder is 11. What is the value of the divisor?


numbers

show that the product of four consecutive even number is always divisible by 384

geometry

A circle of unit radius, houses a square of maximum size inside it. What is the ratio of area of square to area of circle?

Sunday, September 21, 2014

clock puzzle

At how many minutes past 8 O' clock does the minute arm and the hour arm coincide between 8 O' clock and 9 O' clock?

clock puzzle

In an accident the minute arm and the second arm of the wrist watch is lost. The watch now has only the hour arm in the correct position.
What is the minimum time that can be measured accurately?


















number puzzle

Number Puzzle
 












number puzzle

Number Puzzle

 



















Puzzle

A, B and D are good in Hockey and Volleyball. C and A are good in Hockey and Baseball. D and B are good at Cricket and Volleyball. C, D and E are good at Football and Baseball.

Find out, who of the following is good in all the games.

Puzzle

Out of 5 friends A is shorter than B but taller than E. C is tallest and D is little shorter than A. Which one is the shortest?

Puzzle

Nanu and Bhanu are charged for overspeeding on the  Express Highway. Nanu was charged with exceeding the speed limit by 10 km/hr, whereas Bhanu was charged with exceeding the same limit by thrice as much. If Bhanu was driving at 100 km/hr, at what speed was Nanu driving her vehicle?


puzzle

if 6 girls A, B, C, D, E and F have 10 marbles each. A and B take 4 marbles each from D and E respectively. C gives 3 marbles to F who in turn gives 2 marbles to D and 4 marbles to E. E takes back the marbles she had given to B and gives these to C.

Who has got 1 more marble than E?
How many marbles has D less than B?

number puzzle

If 
5 - 4 = 23
8 - 1 = 63
6 - 16 = 32
9 - 9 = 78
3 - 9 = 6
then find the value of 3 - 81 


Puzzle

JMO problems on Direction


Sunday, September 14, 2014

factorization

If, 2x4 + x3 – 11x2 + x + 2 = 0, then find the value of (x + 1/x)

factorization

Factorize: y2 – 4 – x2 + 4x

factorization


Factorize:
9x2+24x
+34+24x-1+9x2


Puzzles

Puzzle --- JMO

An unfortunate mouse has entered the trash compactor whose walls are 15 meters apart. The walls of the compactor begin to close in on the mouse at a speed of 0.2 meter per hour. The mouse panics and starts to runs from one of  walls' that is closing in, to the opposite wall in order to escape, over and over  until the compactor walls meet each other . The mouse runs at a speed of 10 meters per hour. How much distance does the mouse run before it dies?

ICSE mock test paper

ICSE mock test paper for STD X

ICSE mock test paper

ICSE mock test paper STD X

Wednesday, September 3, 2014

JMO - numbers



If you have an operator (!) such that:
1! = 1
2! = 2 x 1
3! = 3 x 2 x 1
And it is also given that 0! = 1
You are given 4 zeros. Can you get a value of 24. You can use the operator as many times as you want.

variation

The intensity of light is measured in Lux. It is found that the intensity of light varies as the inverse square of the distance between light source and point of measurement.
if at 10 meters, the intensity is 100 lux, what is the intensity of the light at 15 meter distance.

percentage

Refer to the path followed by the ball in the diagram below. every time the ball hits the ground it looses 20% of its energy. what is the energy left in the ball just after it hits the ground for the third time.











Monday, September 1, 2014

mensuration



















Ladoos of radius 5 cm rest are stacked in the fashion shown above for the Ganesh Chaturthi. what is the area of the shaded region.

circle














 wooden cubes of unit cross section (1 cm x 1 cm) are used to keep the pipe in place as shown above. What is the horizontal distance between the two cubes.

circle















find the coordinates of point of contact between the bigger and the smaller circle.

circle




















The 2 circles of radius "r" are resting on a horizontal plan. A smaller circle is housed in the gap of the two bigger circles as shown. What is the radius of the smaller circle?