Prime Numbers MCQ Quiz - Objective Question with Answer for Prime Numbers - Download Free PDF
Last updated on Mar 28, 2024
Latest Prime Numbers MCQ Objective Questions
Prime Numbers Question 1:
Which of the following numbers is not a prime number?
Answer (Detailed Solution Below)
Prime Numbers Question 1 Detailed Solution
Solution:
A prime number is a number that is only divisible by 1 and itself. Among the given options:
11 - This number is only divisible by 1 and 11. Thus, it is a prime number.
13 - This number is only divisible by 1 and 13. Thus, it is a prime number.
15 - This number is divisible by 1, 3, 5, and 15. Thus, it is not a prime number.
17 - This number is only divisible by 1 and 17. Thus, it is a prime number.
Therefore, among the given options, the number that is not a prime number is option 3) 15.
Prime Numbers Question 2:
The number 323 has
Answer (Detailed Solution Below)
Prime Numbers Question 2 Detailed Solution
Given:
Number = 323
Concept used:
Prime factors are the prime numbers that multiply together to give a particular integer. Every integer greater than 1 can be uniquely represented as the product of its prime factors.
Calculation:
Prime Factorization of 323 = 17 × 19
∴ The number 323 has two prime factors.
Prime Numbers Question 3:
How many prime numbers are there between 100 and 120?
Answer (Detailed Solution Below)
Prime Numbers Question 3 Detailed Solution
Calculation:
To find the prime numbers between 100 and 120, we'll check each number in that range to see if it is divisible by any number other than 1 and itself.
The numbers between 100 and 120 are: 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, and 120.
we find that the prime numbers between 100 and 120 are: 101, 103, 107, 109, and 113 as these are not divisible by any number except 1.
Therefore, there are five prime numbers between 100 and 120.
∴ Option 3 is the correct answer.
Prime Numbers Question 4:
Which one of the following numbers is a prime number?
Answer (Detailed Solution Below)
Prime Numbers Question 4 Detailed Solution
The answer is 157.
Explanation:-
A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. In other words, it's a number that has exactly two distinct natural number divisors: 1 and itself.
183 = 3 x 61, so it's not a prime number.
121 = 112. This is not a prime since it can be divided evenly by 11.
157 only has 1 and 157 as its divisors, so it's a prime number.
10201 = 1012. This number can be divided evenly by 101, so it is not a prime number.
Prime Numbers Question 5:
What is the next prime number after 5?
Answer (Detailed Solution Below)
Prime Numbers Question 5 Detailed Solution
Top Prime Numbers MCQ Objective Questions
How many prime numbers are there between 100 and 120?
Answer (Detailed Solution Below)
Prime Numbers Question 6 Detailed Solution
Download Solution PDFCalculation:
To find the prime numbers between 100 and 120, we'll check each number in that range to see if it is divisible by any number other than 1 and itself.
The numbers between 100 and 120 are: 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, and 120.
we find that the prime numbers between 100 and 120 are: 101, 103, 107, 109, and 113 as these are not divisible by any number except 1.
Therefore, there are five prime numbers between 100 and 120.
∴ Option 3 is the correct answer.
How many prime numbers are there between 20 and 50?
Answer (Detailed Solution Below)
Prime Numbers Question 7 Detailed Solution
Download Solution PDFCalculation:
The prime numbers between 20 and 50 are:
23, 29, 31, 37, 41, 43, 47
Therefore, there are 7 prime numbers between 20 and 50.
How many Prime Numbers lie between 1 to 30 ?
Answer (Detailed Solution Below)
Prime Numbers Question 8 Detailed Solution
Download Solution PDFGiven:
The prime numbers between 1 to 30.
Concept used:
Prime numbers are numbers which have two factors 1 and itself.
Calculation:
The prime numbers between 1 to 30 is:
⇒ 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29.
∴ The prime numbers between 1 to 30 is 10.
Consider the following statements:
(I) All prime numbers are odd numbers.
(Il) There are only five single digit prime numbers.
(Ill) There are infinitely many prime numbers.
(IV) A prime number has only two factors.
Which of the above statements are true?
Answer (Detailed Solution Below)
Prime Numbers Question 9 Detailed Solution
Download Solution PDFExplanation:
(I) All prime numbers are odd numbers.
2 is a prime number, which is an even number. Thus, false.
(Il) There are only five single-digit prime numbers.
2, 3, 5, 7 are the only single-digit prime numbers. Thus, false.
(Ill) There are infinitely many prime numbers.
There are infinitely many natural numbers. Thus, true.
(IV) A prime number has only two factors.
A prime number has only two factors, 1 and itself. Thus, true.
Hence, the correct option is (III) and (IV).
How many prime numbers are there between 40 and 50?
Answer (Detailed Solution Below)
Prime Numbers Question 10 Detailed Solution
Download Solution PDFConcept Used:
A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.
Calculation:
The prime numbers between 40 and 50 are 41, 43, and 47. So, there are 3 prime numbers between 40 and 50.
∴ Option 3 is the correct answer.
There are four prime numbers taken in ascending order. The product of the first three prime numbers is 1771 and the sum of the last two prime numbers is 82. What is the product of the last two prime numbers?
Answer (Detailed Solution Below)
Prime Numbers Question 11 Detailed Solution
Download Solution PDFGiven:
The product of the first three prime numbers is 1771.
The sum of the last two prime numbers is 82.
Concept used:
If the product of the first three prime numbers is given then Each divisible quotient will be a prime number.
Calculation:
Let x, y, z, w will be Four prime numbers in ascending order.
=> xyz = 1771
=> 7 × 11 × 23 = 1771
Hence, the first three prime numbers are i.e. x = 7, y = 11, and z = 23.
The Sum of the last two prime numbers i.e. z + w = 82
=> 23 + w = 82
=> w = 59
Now we call easily calculate the Product of the last two prime numbers as
=> zw = 23 × 59 = 1357.
Hence, the product of the last two prime numbers is '1357'.
A two-digit number, 9A, is a prime number. Find A.
Answer (Detailed Solution Below)
Prime Numbers Question 12 Detailed Solution
Download Solution PDFThe Correct Answer is '7"
Calculation:
The only digit prime when 9 is in tenth place is 97
Even numbers can't be prime and other odd numbers between 90 and 99 have factors.
⇒ 91 has 13 and 7
⇒ 93 has 31 and 3
⇒ 95 has 19 and 5
⇒ 99 has 9 and 11
so the answer is A = 7
Note: A number that is divisible only by itself and 1 is called a prime number.
Which of the following pairs represents the co-prime numbers?
Answer (Detailed Solution Below)
Prime Numbers Question 13 Detailed Solution
Download Solution PDFGiven:
Option 1: (15, 141)
Option 2: (15, 94)
Option 3: (15, 235)
Option 4: (51, 141)
Concept:
Co-prime numbers are numbers that have only 1 as their common factor.
Calculation:
Option 1: (15, 141) = common factor except 1 is 3
Option 2: (15, 94) = common factor 1
Option 3: (15, 235) = common factor except 1 is 5
Option 4: (51, 141) = common factor except 1 is 3
⇒ Only (15, 94) are co-prime numbers as their only common factor is 1.
Therefore, the pair (15, 94) represents the co-prime numbers.
Sum of all the prime numbers between 70 and 100 is :
Answer (Detailed Solution Below)
Prime Numbers Question 14 Detailed Solution
Download Solution PDFConcept:
Prime numbers: Any natural number greater than 1 divisible only by itself and 1.
Calculation:
Prime numbers are = 71, 73, 79, 83, 89, 97
⇒ Sum = 71 + 73 + 79 + 83 + 89 + 97 = 492
∴ The sum of all the prime numbers between 70 and 100 is 492.
The correct option is 1 i.e. 492a and b are two positive integers such that the least prime factor of a is 3 and least prime factor of b is 5. The least prime factor of a + b is
Answer (Detailed Solution Below)
Prime Numbers Question 15 Detailed Solution
Download Solution PDFConcept Used:-
For an integer, the least prime factor is the smallest prime number that can divide this integer.
Explanation:-
Given a and b are two positive integers.
Here, the least prime factor of a = 3
Which is an odd number
Also the least prime factor of b = 5.
It is also an odd number.
Now, we have to find the least prime factor of a + b. Since we know that the sum of two odd numbers is even. So, the least prime factor of a + b should be even.
In the given options we have 2 and 8 as even numbers. Here, 2 is one of the factors of 8. Here 8 is not a prime number.
Thus, 2 is the least positive factor until a + b is a prime number of more than two
Hence, the correct option is 1.