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0 votes
2 answers
100 views

Directly proof $S$ is countable, where $S$ is set of function from $\{0, 1\}$ to $\mathbb{N}$

Suppose $S=\{f_1,f_2,f_3,f_4,f_5,........\}$ where $f_i$ is a function $f:\{0, 1\}\to\mathbb{N}.$ I have to prove $S$ is countable.Then need to prove direct one-to-one correspondence between $S$ and $\...
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0 votes
3 answers
165 views

Let set A is subset of set $\{{1,2,3,...,100}\}$ which has $55$ different elements.

Let set $A \subset\{{1,2,3,...,100}\}$ with $55$ distinct elements. Prove that there exist two elements in $A$ which have a difference of 10. I understand that the common thing is that we take more ...
Spameris's user avatar
  • 425
1 vote
1 answer
42 views

Natural Number Inductive Proof

Prove the following statement: For every $\lambda$>1, there exists a number a��N and b∈[0,1) such that $\lambda$=a+b. I first defined a = sup{n ∈ N | n ≤ x}, so m is the integer part of x or the ...
james black's user avatar
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