31 Answered Questions for the topic Set Theory


Set Theory Question

Prove f(a1∩f^-1(b2)=f(a1)∩b2


Problem on two variable polynomial inequalities (Probably a diophantine inequality !!)

Consider the sets defined by the real solutions of the inequalities :A = { ( x , y ) : x2 + y4 ≤ 1} B = { ( x , y ) : x4 + y6 ≤ 1}Then... more


What are ways to use the palindromic property of a palindromic scale?

A palindromic scale, as I've seen it described on a number of music theory websites, is defined as one whose sequence of intervals is the same when ascending and descending. For instance: D Dorian... more


State the number of elements in the set, if possible

A={×:×∈Ζ, -6<×≤4}


Set builder notation translation and cardinality

Given the following:S = {(A, B) | A ⊆ {1, 2, . . . , n}, B ⊆ {1, 2, . . . , n}, |A ∩ B| ≥ 1}, how can I translate this in terms of english and how would one go about finding the cardinality of the... more


If A and B are subsets of the universal set U , then show that

A⊂B⇔A∪B=B , without the use of Venn-Euler diagram.


on set theory

Every resident of a city can speak Hindi or English. If 75 % of the population speaks Hindi and 60% speaks English, then what percentage can speak both the languages ?


Set Theory/Math Logic

Is there any way to prove that   - Every point in A intersect B is greater than or equal to 1?   - The intersection of two sets has a point in commonwith another set?   If there is no way to... more


Let X: [0,1] being in all real numbers be given by X(x) = max{x-0.5,0}. Find the inverse images of all intervals [a,b]

Let X: [0,1] being in all real numbers be given by X(x) = max{x-0.5,0}. Find the inverse images of all intervals [a,b] Due to lack of examples related to the theory, I am unable to properly write... more


J={x|x 4 - 2x is less than equal to 10 ^ x € z}

Convert it into roster form. 


Venn diagram word problem

A survey of 100 school children was taken to determine how they liked their ice cream. It was found that: 55 like vanilla,90 liked at least one of the flavors 50 do not like chocolate,35 liked... more


Dont understand natural number+ symbol. what does it mean

I know and understand what natural numbers are, but what does it mean when the natural number symbol has a + at the top, in the position the squared number would be. Can't seem to find information... more


Of 540 students, 335 like hamburgers and 287 like hotdogs. 220 like both.

1. How many students don't like either? 2. ~hamburgers=


In a survey 113 business executives were asked if they regularly read the Wall Street Journal, Business Week, and Tampa Bay Times.

87 read Journal, 74 read Business, 88 read Times, 56 read Journal and Business, 55 read Business and Times, 67 read Journal and Times, 42 read all 3. 1. How many read only the Wall Street... more


Discrete Math / Set Theory - Proof

Hi I have 2 problems that I need to say whether or not they are true or not and then write a proof for my answer. I am really struggling and could use a little help thank you   1)        (X ⊆ Y... more


Is it possible to find different combinations of subsets which cover the original set?

for example if A = {a,b,c} then all possible subsets are {a}, {b}, {c}, {a,b}, {a,c}, {b,c},{a,b,c} and combinations of subsets which cover the original set are: {{a},{b,c}} and {{a},{b},{c}} and... more


What is the set of northeastern states NE ?

thats pretty much it 


Think about R the set of real numbers. Are there any exceptions for any of its subsets being uncountable? If they exist, what are they?

Professor says this question is a lot simpler than I think 


Show that a subset with K elements has 2^k possible subsets

set theory 


Let's say you have your email has a set total of 315 total messages how many subsets can you possibly create

This is a set theory problem my teacher say its easier than I think but I don't understand. 


principal ideal ring

Suppose thatR=R1⊕R2⊕…….⊕Rnwhere each Ri is a principal ideal ring. Verify that R is also a principal ideal ring.   please I want help with that  


Let A and B be subsets of U, n(U) = 100, n(A union B)' = 37, n(B-A)=40. Find n(A).

I can't find an example of how to solve when n(A) and n(B) are not given. Please help.


i have deficulty with this three questions that I need to solve and really need help as soon as possible

Let U={w, x, y,1, 2, 3} , A ={2, y} , B = {x, y, 3}, C ={w, y,1}   Find AU B' Find n(B-A)  find AXB

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