What is the sum of all prime numbers between 1 and 20?

Question

Accepted Answer

To find the sum of all prime numbers between 1 and 20, follow these steps:

1. **Identify Prime Numbers**:  
   Prime numbers are natural numbers greater than 1 that have no divisors other than 1 and themselves. The prime numbers between 1 and 20 are:  
   $$2, 3, 5, 7, 11, 13, 17, 	ext{and }19.$$

2. **Add the Prime Numbers**:  
   Sum these numbers step by step:  
   $$2 + 3 = 5$$  
   $$5 + 5 = 10$$  
   $$10 + 7 = 17$$  
   $$17 + 11 = 28$$  
   $$28 + 13 = 41$$  
   $$41 + 17 = 58$$  
   $$58 + 19 = 77$$

3. **Final Answer**:  
   The sum of all prime numbers between 1 and 20 is **77**.

Thus, the correct answer is **c) 77**.

Answer

Answer

Answer