How many of the numbers between 20 and 40 are prime?
Show Hint
- 3
- 4
- 5
- 6
- 7
The Correct Option is B
Solution and Explanation
Final Answer: \[ \boxed{4} \]
Top Questions on Number System
Find the residue of \( (67 + 89 + 90 + 87) \pmod{11} \):
- CUET (PG) - 2025
- Mathematics
- Number System
Match List-I with List-II and choose the correct option:
LIST-I (Infinite Series) LIST-II (Nature of Series) (A) \( 12 - 7 - 3 - 2 + 12 - 7 - 3 - 2 + \dots \) (II) oscillatory (B) \( 1 - \frac{1}{2} + \frac{1}{3} - \frac{1}{4} + \dots \) (IV) conditionally convergent (C) \( \sum_{n=0}^{\infty} \left( (n^3+1)^{1/3} - n \right) \) (I) convergent (D) \( \sum_{n=1}^{\infty} \frac{1}{n \left( 1 + \frac{1}{n} \right)} \) (III) divergent
Choose the correct answer from the options given below:- CUET (PG) - 2025
- Mathematics
- Number System
Match List-I with List-II and choose the correct option:
LIST-I (Set) LIST-II (Supremum/Infimum) (A) \( S = \{2, 3, 5, 10\} \) (III) Sup S = 10, Inf S = 2 (B) \( S = (1, 2] \cup [3, 8) \) (IV) Sup S = 8, Inf S = 1 (C) \( S = \{2, 2^2, 2^3, \dots, 2^n, \dots\} \) (II) Sup S = 5, Inf S = -5 (D) \( S = \{x \in \mathbb{Z} : x^2 \le 25\} \) (I) Inf S = 2
Choose the correct answer from the options given below:- CUET (PG) - 2025
- Mathematics
- Number System
Which of the following are correct?
A. A set \( S = \{(x, y) \mid xy \leq 1 : x, y \in \mathbb{R}\} \) is a convex set.
B. A set \( S = \{(x, y) \mid x^2 + 4y^2 \leq 12 : x, y \in \mathbb{R}\} \) is a convex set.
C. A set \( S = \{(x, y) \mid y^2 - 4x \leq 0 : x, y \in \mathbb{R}\} \) is a convex set.
D. A set \( S = \{(x, y) \mid x^2 + 4y^2 \geq 12 : x, y \in \mathbb{R}\} \) is a convex set.
- CUET (PG) - 2025
- Mathematics
- Number System
If p is a prime number and a group G is of the order p2, then G is:
- CUET (PG) - 2025
- Mathematics
- Number System
Questions Asked in GRE exam
If the operation \( x \, ¤, y = 4x - y^2 \), and \( x, y \) are positive integers, which of the following cannot produce an odd value?
- GRE - 2024
- Algebra
- The system of equations is: \[ 7x + 3y = 12 \\ 3x + 7y = 6 \] If \(x\) and \(y\) satisfy the system of equations, what is the value of \(x - y\)?
- GRE - 2024
- Linear Equations
The total amount of Judy’s water bill for the last quarter of the year was \(\$ 40.50\). The bill consisted of a fixed charge of \(\$ 13.50\) plus a charge of \(\$ 0.0075\) per gallon for the water used in the quarter. For how many gallons of water was Judy charged for the quarter?
- GRE - 2024
- Linear Equations
- Find the number of words formed by permuting all the letters of the word INDEPENDENCE such that the E’s do not come together.
- GRE - 2024
- permutations and combinations
- A box contains 5 red and 4 blue balls. In how many ways can 4 balls be chosen such that there are at most 3 balls of each colour?
- GRE - 2024
- permutations and combinations