31 Answered Questions for the topic Prime Numbers

10/03/20

How would you factorise an equation with no factors?

So I need to factorise the equation: x2-5x-7=0I have learned how to do this before, but can’t for the life of me remember or find the theory for it.Thanks if you can lend me a hand!
Prime Numbers Algebra 2 Maths Exponents

01/29/20

Quadratic equations: variables in exponents using prime numbers

I can't find the solution, could I get some help please?22x - 24.2x + 128 = 0 thanks for the help
Prime Numbers

01/07/20

Composite prime numbers

What composite numbers less the 20 have more than five factors

03/19/19

Are all highly composite numbers even?

A highly composite number is a positive integer with more divisors than any smaller positive integer. Are all highly composite numbers even (excluding 1 of course)? I can't find anything about this... more

Can it be proven/disproven that there are highly composite numbers that prime-factorize into larger primes such as $9999991$?

Of course, following the rules found by Ramanujan, such a highly composite number would need to factorize into all primes ascending up to 9999991 (with descending powers as the primes progress) so... more

When is $4n^4+1$ prime?

Find all natural numbers $n$ such that $4n^4+1$ is prime. $4n^4+1$ is obviously prime when $n=1$. But can we prove that no other $n$ works?

How many primes do I need to check to confirm that an integer $L$, is prime?

I recently saw the 1998 horror movie "Cube", in which a character claims it is humanly impossible to determine, by hand without a computer, if large (in the movie 3-digit) integers are prime... more
Prime Numbers Gre Factoring Gre Exam

03/13/19

Is 440 a factor of 72840?

I would like to know how to solve the following question: Is 440 a factor of 72840? I would have thought that this involves dividing 72840 by 440 and seeing if it produces an integer. However, the... more

11/17/17

If n!+1 is prime, is n prime?

Just wondering if this is true or false!
Prime Numbers Prime Factorization

09/21/17

Maritza remembers her PIN because it is between 1000 and 1500 and it is the product of two consecutive prime numbers. What is her PIN

Marie remembers her PIN because it is between 1000 and 1500 and it is the product of two consecutive prime numbers. What is her PIN?
Prime Numbers

05/03/17

Put a check by all the prime numbers.

23491124Noneoftheabove
Prime Numbers

02/07/17

why cant 7 be the difference of any prime number?

i have to prove why 7 cant be the difference of any prime number
Prime Numbers

09/21/16

Are any prime gaps end larger than the square of the prime?

I am not trained in mathematics at all and I was thinking about a certain problem. I'm not sure if there's a name for this problem or how to search for work done on it before.   Assume the... more
Prime Numbers Real Numbers

09/14/16

a boy with a collection of marbles realises that if he makes a group of five or six marbels at a time there are always two marbles left can you explain why the

confused between concept of real numbers and prime number used in the question
Prime Numbers Math Equations Math Help

03/19/16

Prime numbers

is there an easier way to find out how many prime numbers are under 100 without going through each number? Thanks!

02/03/16

Prime number word problem..

Brenda is thinking of a prime number between 40 and 50. Josh is thinking of a prime number between 10 and 20. The difference between the two numbers is 26. What are the two numbers?
Prime Numbers

01/28/16

Find the smallest possible value of the whole number

Find the smallest possible value of the whole number "y" such that the product of "y" and 6600 is a square number.To make two identical numbers from 6600 x Y, we add prime numbers to the product.
Prime Numbers

10/29/15

Which number is prime? 26 or 9 or 5 or 6

which number is prime?
Prime Numbers

09/28/15

Which list contains only one prime number ? (A) 3,4,5,6 (B) 6,9,10,11 (C) 4,10,12,21 (D) 7,11,13,17......

I got this question when I was doing my SOF Olympiad Practice.The Solution say's the answer is (B).But I don't understand how.....
Prime Numbers Probability

09/15/15

Probabilty for first 10 prime numbers pulled out of a hat

Each of the first ten prime numbers is written on an individual piece of paper and put into a hat. If two are drawn at once, so that means without replacement, what is the probability that the sum... more

Weird prime numbers question

The sum of 2 postive prime numbers is a prime number and 3 times that sum is an odd number. Which of the following prime numbers must be one of the original prime... more
Prime Numbers Maths

06/23/15

Show that this equation is true

It is given that p is a prime number and p > 5. a) Show that p= 6n + 1 or p = 6n + 5 for some positive integer n. b) Hence, show that p2 + 2 is divisible by 3.   How can I 'show that'? With... more
Prime Numbers

11/27/14

Which of the following is not a prime number? A. 11 B. 19 C. 5 D. 24

-Which of the following is not a prime number? A. 11 B. 19 C. 5 D. 24

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