Advertisements
Advertisements
Question
State which of the following statement are true and which are false. Justify your answer.
28 ∈ {y | the sum of the all positive factors of y is 2y}
Options
True
False
Advertisements
Solution
This statement is True.
Explanation:
Since, the sum of positive factors of 28
= 1 + 2 + 4 + 7 + 14 + 28
= 56
= 2(28)
APPEARS IN
RELATED QUESTIONS
Identify whether the following is set or not? Justify your answer.
A team of eleven best-cricket batsmen of the world.
Identify whether the following is set or not? Justify your answer.
A collection of most dangerous animals of the world.
Write the following set in roster form:
C = {x : x is a two-digit natural number such that the sum of its digits is 8}
List all the elements of the following set:
A = {x : x is an odd natural number}
List all the elements of the following set:
C = {x : x is an integer, x2 ≤ 4}
List all the elements of the following set:
D = {x : x is a letter in the word “LOYAL”}
Which of the following collection are sets? Justify your answer:
The collection of difficult topics in mathematics.
Describe the following sets in Roster form:
{x : x is a letter before e in the English alphabet}
Describe the following set in Roster form:
The set of all letters in the word 'Trigonometry'
Describe the following sets in set-builder form:
B={1,1/2 ,1/3, 1/4,1/5,...........};
Describe the following sets in set-builder form:
C = {0, 3, 6, 9, 12, ...}
Describe the following sets in set-builder form:
{5, 25, 125 625}
Match each of the sets on the left in the roster form with the same set on the right described in the set-builder form:
| (i) | {A, P, L, E} | (i) | x : x + 5 = 5, x ∈ Z |
| (ii) | {5, −5} | (ii) | {x : x is a prime natural number and a divisor of 10} |
| (iii) | {0} | (iii) | {x : x is a letter of the word "RAJASTHAN"} |
| (iv) | {1, 2, 5, 10,} | (iv) | {x: x is a natural number and divisor of 10} |
| (v) | {A, H, J, R, S, T, N} | (v) | x : x2 − 25 = 0 |
| (vi) | {2, 5} | (vi) | {x : x is a letter of the word "APPLE"} |
Which of the following statement are correct?
Write a correct form of each of the incorrect statements.
\[a \subset \left\{ a, b, c \right\}\]
Which of the following statement are correct?
Write a correct form of each of the incorrect statement.
\[\left\{ a \right\} \subset \left\{ \left\{ a \right\}, b \right\}\]
Which of the following statement are correct?
Write a correct form of each of the incorrect statement.
\[\left\{ b, c \right\} \subset \left\{ a, \left\{ b, c \right\} \right\}\]
Let A = {a, b, {c, d}, e}. Which of the following statement are false and why?
\[\left\{ c, d \right\} \subset A\]
Let A = {a, b, {c, d}, e}. Which of the following statement are false and why?
\[\left\{ c, d \right\} \in A\]
Let A = {{1, 2, 3}, {4, 5}, {6, 7, 8}}. Determine which of the following is true or false:
\[1 \in A\]
Let U = {1, 2, 3, 4, 5, 6, 7, 8, 9}, A = {1, 2, 3, 4}, = {2, 4, 6, 8} and C = {3, 4, 5, 6}.
Find \[\left( A \cap C \right)'\]
Let U = {1, 2, 3, 4, 5, 6, 7, 8, 9}, A = {2, 4, 6, 8} and B = {2, 3, 5, 7}. Verify that \[\left( A \cap B \right)' = A' \cup B'\]
Let A = {1, 2, 3, 4, 5, 6}. Insert the appropriate symbol ∈ or ∉ in the blank space:
0 ____ A
Describe the following set in Set-Builder form
{0, ±1, ±2, ±3}
If A = {x/6x2 + x – 15 = 0}, B = {x/2x2 – 5x – 3 = 0}, C = {x/2x2 – x – 3 = 0} then find (A ∪ B ∪ C).
If A = {x/6x2 + x – 15 = 0}, B = {x/2x2 – 5x – 3 = 0}, C = {x/2x2 – x – 3 = 0} then find (A ∩ B ∩ C)
From amongst 2000 literate individuals of a town, 70% read Marathi newspapers, 50% read English newspapers and 32.5% read both Marathi and English newspapers. Find the number of individuals who read Only one of the newspapers
In a hostel, 25 students take tea, 20 students take coffee, 15 students take milk, 10 students take bot tea and coffee, 8 students take both milk and coffee. None of them take tea and milk both and everyone takes at least one beverage, find the total number of students in the hostel.
There are 260 persons with skin disorders. If 150 had been exposed to the chemical A, 74 to the chemical B, and 36 to both chemicals A and B, find the number of persons exposed to Chemical A or Chemical B
Write the following interval in Set-Builder form
`(6, ∞)`
Write the following interval in Set-Builder form.
(2, 5]
Select the correct answer from given alternative.
In a city 20% of the population travels by car, 50% travels by bus and 10% travels by both car and bus. Then, persons travelling by car or bus are
State which of the following statement are true and which are false. Justify your answer.
37 ∉ {x | x has exactly two positive factors}
State which of the following statement is true and which is false. Justify your answer.
3 ∉ {x | x4 – 5x3 + 2x2 – 112x + 6 = 0}
In a group of 50 students, the number of students studying French, English, Sanskrit were found to be as follows:
French = 17, English = 13, Sanskrit = 15 French and English = 09, English and Sanskrit = 4 French and Sanskrit = 5, English, French and Sanskrit = 3. Find the number of students who study English only
In a group of 50 students, the number of students studying French, English, Sanskrit were found to be as follows:
French = 17, English = 13, Sanskrit = 15 French and English = 09, English and Sanskrit = 4 French and Sanskrit = 5, English, French and Sanskrit = 3. Find the number of students who study none of the three languages
In a class of 60 students, 25 students play cricket and 20 students play tennis, and 10 students play both the games. Then, the number of students who play neither is ______.
If A and B are any two sets, then A – B is equal to ______.
