You want to send a valuable object to a friend& You have a box to send the object.

The box has a locking ring which is more than large enough to have a lock attached

You and your friend have several locks with keys.

Butthe problem is that your friend does not have the key to any lock that you have, and vice versa. How do you do it?

Note: you cannot send a key in an unlocked box

For Solution SCROLL DOWN...

Solution:

Attach a lock to the ring. Send it to her. She attaches her own lock and sends it back. You remove your lock and send it back to her. She removes her lock.

simple

### PUZZLE

### square of numbers in 100's

Posted by
SHRENIK
on Wednesday, September 16, 2009

Labels:
SQUARE OF A NUMBER
/
Comments: (6)

> Choose a number over 100 (START WITH SMALLER NUMBER).

> The last two places will be the square of

the last two digits (keep if any carry) _ _ _ X X.

> The first three places will be the number plus

the last two digits plus any carry: X X X _ _.

here is an Example:

> let the number be 108:

2. Square the last two digits (no carry): 8 × 8 = 64: _ _ _ 64

3. Add the last two digits to the number: 108 + 08= 116:

so 1 1 6 _ _

4. So 108 × 108 = 11664.

> The last two places will be the square of

the last two digits (keep if any carry) _ _ _ X X.

> The first three places will be the number plus

the last two digits plus any carry: X X X _ _.

here is an Example:

> let the number be 108:

2. Square the last two digits (no carry): 8 × 8 = 64: _ _ _ 64

3. Add the last two digits to the number: 108 + 08= 116:

so 1 1 6 _ _

4. So 108 × 108 = 11664.

### FIND SQUARE OF NUMBERS IN 200 TO 299

Posted by
SHRENIK

Labels:
FUN WITH NUMBERS,
SQUARE OF A NUMBER
/
Comments: (2)

steps to find square of numbers in 200's

> Choose a number in the 200s (start with numbers under 210, then try for larger ones).

>The first digit of the square is 4: 4 _ _ _ _

> The next two digits will be 4 times the last 2 digits: _ X X _ _

> The last two places will be the square of the last digit: _ _ _ X X

here we take an Example:

> let the number be 207:

> The first digit is 4

so 4 _ _ _ _

> The next two digits are 4 times the last digit:

4 × 7 = 28

so _ 2 8 _ _

Square the last digit: 7× 7 = 49

so _ _ _ 49

So finally we get 206 × 206 = 42849.

and For larger numbers work right to left:

> Square the last two digits (keep the carry): _ _ _ X X

> 4 times the last two digits + carry: _ X X _ _

> Square the first digit + carry: X _ _ _ _

example

>If the number to be squared is 225:

> Square last two digits (keep carry):

25x25 = 625 (keep 6): _ _ _ 2 5

> 4 times the last two digits + carry:

4x25 = 100; 100+6 = 106 (keep 1): _ 0 6 _ _

> Square the first digit + carry:

2x2 = 4; 4+1 = 5: 5 _ _ _ _

> So 225 × 225 = 50625.

> Choose a number in the 200s (start with numbers under 210, then try for larger ones).

>The first digit of the square is 4: 4 _ _ _ _

> The next two digits will be 4 times the last 2 digits: _ X X _ _

> The last two places will be the square of the last digit: _ _ _ X X

here we take an Example:

> let the number be 207:

> The first digit is 4

so 4 _ _ _ _

> The next two digits are 4 times the last digit:

4 × 7 = 28

so _ 2 8 _ _

Square the last digit: 7× 7 = 49

so _ _ _ 49

So finally we get 206 × 206 = 42849.

and For larger numbers work right to left:

> Square the last two digits (keep the carry): _ _ _ X X

> 4 times the last two digits + carry: _ X X _ _

> Square the first digit + carry: X _ _ _ _

example

>If the number to be squared is 225:

> Square last two digits (keep carry):

25x25 = 625 (keep 6): _ _ _ 2 5

> 4 times the last two digits + carry:

4x25 = 100; 100+6 = 106 (keep 1): _ 0 6 _ _

> Square the first digit + carry:

2x2 = 4; 4+1 = 5: 5 _ _ _ _

> So 225 × 225 = 50625.

### QUIZ

Posted by
SHRENIK
on Friday, July 24, 2009

Labels:
FUN,
FUN WITH NUMBERS
/
Comments: (10)

can anyone make 3 using two 2's???

ONE ANSWER IS

2^0 + 2=3

IF YOU HAVE ANY ANSWER POST IT AS COMMENT........

ONE ANSWER IS

2^0 + 2=3

IF YOU HAVE ANY ANSWER POST IT AS COMMENT........

### EASY MULTIPLICATION TRICK

Posted by
SHRENIK

Labels:
FUN WITH NUMBERS,
multiply
/
Comments: (1)

Method for multiplying numbers where the first figures are the same and the last figures add up to 10

FOR EG:

32 x 38 = 1216

Both numbers here start with 3 THEY ARE SAME and the last

figures (2 and 8) add up to 10

So we just multiply 3 by 4 (the next number up)

to get 12 for the first part of the answer.

And we multiply the last figures: 2 x 8 = 16 to

get the last part of the answer.

· And 81 x 89 = 7209

We put 09 since we need two figures as in all the other examples

FOR EG:

32 x 38 = 1216

Both numbers here start with 3 THEY ARE SAME and the last

figures (2 and 8) add up to 10

So we just multiply 3 by 4 (the next number up)

to get 12 for the first part of the answer.

And we multiply the last figures: 2 x 8 = 16 to

get the last part of the answer.

· And 81 x 89 = 7209

We put 09 since we need two figures as in all the other examples

### MATHS PUZZLE

Posted by
SHRENIK

Labels:
FUN,
FUN WITH NUMBERS,
MATHS,
PUZZLE
/
Comments: (7)

solve this

Village A has a population of 70,000, which is decreasing at the rate of 1000 per year.

Village B has a population of 52000, which is increasing at the rate of 400 half yearly

.How many years will they take to reach same population

try its easy .............

leave your answer as a comment......

ANSWER

let,after x yrs their will b same...

after x yrs in A population decreases 1000x & in B population increases (2*400*x)=800x .

So,

70000-1000x = 52000 + 800x

x= 10

Village A has a population of 70,000, which is decreasing at the rate of 1000 per year.

Village B has a population of 52000, which is increasing at the rate of 400 half yearly

.How many years will they take to reach same population

try its easy .............

leave your answer as a comment......

ANSWER

let,after x yrs their will b same...

after x yrs in A population decreases 1000x & in B population increases (2*400*x)=800x .

So,

70000-1000x = 52000 + 800x

x= 10