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## #1 2006-11-04 10:12:17

Prakash Panneer
Member
Registered: 2006-06-01
Posts: 110

Assignment-22

1)If  (2.5)^x = (0.025)^y = 10^3 then find 1/x-1/y.

2)If  log 2  =  0.3010 then find the number of digits  in   1024^1024.

3)If  log 3 = a , log 2 = b then express log 5 6 interms of  'a' and 'b' .

4)If  n is a positive integer then show that  (1111111.....1111)   -   (222222.....2222) is the square of positive integer.                2n times                       n times

5)Out of a group of 20 teachers in a school, 10 teach Mathematics, 9 Physics and 7 Chemistry, 4 teach Math's and Physics and none teach both Math's and Chemistry. How many teach physics only?

6)If  X is a finite set . Let P(X) denote the set of all subsets of  X and  n(X) denote the number of elements in X . If for two finite subsets A, B, n(p(A)) = n(p(B)) + 15. Then find  n(B) and n(A).

7)If  n(U) = 60, n(A) = 21, n(B) = 43 then find  (i) Greatest value of  n ( A U B )
(ii)Least value  of n (AUB)
(iii) Greatest value of  n ( A ∩ B )
(iv)Least value  of n (A∩B)

8)If n(A) = 50, n(B) = 20 and n(A ∩B) = 10     then find  n ( A U B ) ,
n ( A - B ), n ( A ∆ B ).

9)Find the number of integral solutions of x^2-y^2=2006.

10)Find the number of positive integers less than one million whch the digts 5,6,7,8,9,0 do not appear.

Letter, number, arts and science
of living kinds, both are the eyes.

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## #2 2006-11-04 15:38:08

Ricky
Moderator
Registered: 2005-12-04
Posts: 3,791

Prakash, you have consistently just posted problems to this forum without showing any attempt to do them yourself.  Please, if you wish to recieve help, show you've done some work and ask specific questions.

We are here to help.  We are not here to do your work for you.

"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

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## #3 2006-11-04 19:51:49

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

It's nature's way for people to ask for help without having an attempt first. And we are here to block that force of nature.

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## #4 2006-11-08 02:55:07

emmajane
Member
Registered: 2006-11-08
Posts: 1

Please Help    I have numbers 4 5 5 7 (can use only once Any way add, subtract, multiply or divide) needs to equal 24
I have done everything but only come up with 25 once & 26 several times.  how do I get to 24?

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## #5 2006-11-08 05:26:13

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900