1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
katrin [286]
3 years ago
9

Let's say we want to check whether a number N is a prime number or not. The idea to solve this problem is to iterate through all

the numbers starting from 2 to N using a loop and for every number check if it divides N. If you find any number that divides, we conclude that N is not prime (you should break from the loop as you don't need check further for this number). If we did not find any number between 2 and N which divides N then it means that N is prime. But one challenge could arise when you need to know the reason why your loop breaks. Is it because we managed to divide or is it that the loop completed?

English
2 answers:
riadik2000 [5.3K]3 years ago
7 0

Answer:

I am writing a Python program.    

N = int(input("Enter a number: "))      # prompts user to enter a number

if N > 1:  #if the input number is greater than 1

  for k in range(2,N):   # loop starts which iterates from 2 to input number

      if (N % k) == 0:   # if input number is divisible by value in k

          print(N,"is not a Prime Number")  #displays input no. is not prime

          break   #terminates the loop

  else:   # if input numbers is not divisible by any value in k

      print(N,"is a Prime Number")     # displays that input number is prime

else:   # if the input number is less than or equal to 1

     print(N,"is not greater than 1 and is not a prime number")  

Explanation:

Lets take a value of N to understand the above program.

Suppose the user enters the value 5.

This value is stored in N variable.

If condition checks if the value entered by the user is greater than 1. This condition evaluates to true because 5>1

So the program flow enters the loop. The loop has a range() function is used for the iteration purpose in the loop. It will iterate generating the numbers in the given range which means starting from 2 and ending at N (5 here).

If condition in the loop checks if the input number N which is 5 is completely divisible by any number in the given range i.e. from 2 until it reaches N. Mod operator % is used here because if the N is divisible by any number in the range then its remainder will be 0.  If  this condition evaluates to true this means that N is not a prime number as the prime number is only divisible by 1 and itself. So if this condition is true then the line 5 is not a Prime Number is displayed in the output.

At every iteration the mod of number 5 and each number in the given range is computed and is checked if the result is 0 e.g 5%2 = 1 , 5%3 = 2, 5%4 = 1 and none of the result is equal to 0 so this means 5 is a prime number.

If the condition evaluates to False this means that the number N is prime as it is not divisible by any number in the given range. So the line 5 is a Prime Number is printed on the screen as output.

The last else part is executed when the first outer if condition evaluates to false which means if N is less than 1 and this line 5 is not greater than 1 and is not a prime number is printed as result.

Bess [88]3 years ago
6 0

Answer:

1) its because we managed to divide the answer so it is not a prime number.

2)

Code:

#include <stdio.h>

int main()

{

   int i, j, n, isPrime; // isPrime is used as flag variable

   /* Input upper limit to print prime */

   printf("Enter your n : ");

   scanf("%d", &n);

   printf("Prime numbers from 1 to %d:\n", n);

   /* Find all Prime numbers between 1 to n */

   for(i=2; i<=n; i++)

   {

       /* Assume that the current number is Prime */

       isPrime = 1;  

       /* Check if the current number i is prime or not */

       for(j=2; j<=i/2; j++)

       {

           /*

            * If i is divisible by any number other than 1 and self

            * then it is not prime number

            */

           if(i%j==0)

           {

               isPrime = 0;

               break;

           }

       }

       /* If the number is prime then print */

       if(isPrime==1)

       {

           printf("%d,\n ", i);

       }

   }

   return 0;

}

You might be interested in
Who first mentions Goody Good and Goody Osburn as witches?<br> Why might this be important?
Dimas [21]

Answer:

bc gooba goofy boshoopy

Explanation:

4 0
3 years ago
Read 2 more answers
Which answer best completes the sentence below? Tasha's father her to the dinner next Saturday. o are accompanying o will be acc
krek1111 [17]

Answer:

Its b i think im not that sure

Explanation:

8 0
2 years ago
What does Ronald givens look like to the narrator?
Marysya12 [62]

Answer ; a turtle (A.)

7 0
4 years ago
Read 2 more answers
Lady Macbeth is among Shakespeare's most powerful female characters. Which two sections in this excerpt from Macbeth show that s
8_murik_8 [283]

-She plots a murder against Duncan

-she is more ambitious than her husband

7 0
3 years ago
Read 2 more answers
How long ago was this picture taken? How many rooms do you think are in this house? Does anyone still live here? Do you
Arturiano [62]

Answer:

There’s no photo or reading? How can I answer without this

Explanation:

7 0
3 years ago
Other questions:
  • When should you check the basic elements of your​ essay?
    12·1 answer
  • Latitia had 12 marbles . After she gave 2 marbles to Emilia she has 10/12 of her marbles left . What fraction of the marbles did
    13·2 answers
  • What figure of speech is illustrated in this sentence? "All the world is a stage, and all the men and women merely players."
    5·1 answer
  • Which of the following sentences contains a mental action verb
    5·1 answer
  • Which sentence uses the word stance properly
    7·2 answers
  • I need Help i have 3mins left before this is due: D brainest if anwer
    8·1 answer
  • What are some good interesting things about 3D-Printing?
    5·2 answers
  • 1. A unit that measures the amount of energy provided by food is known as a______________. *
    13·1 answer
  • (For a Friend, do not answer unless you want notifs spamming your phone)
    14·1 answer
  • List three important about the gods and goddesses of ancient Greece. can you hurry, please
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!