Prime numbers — Compute the sum of the first four prime numbers (in increasing order). Show the primes you add to avoid mistakes.

Introduction / Context:This checks recognition of prime numbers and accurate addition. Primes are integers greater than 1 with exactly two distinct positive divisors: 1 and the number itself. Listing the earliest primes and adding them carefully produces the correct sum quickly.

Given Data / Assumptions:

• We need the first four prime numbers in ascending order.
• Definition of prime excludes 1 and includes 2 as the only even prime.
• Perform a direct sum once identified.

Concept / Approach:Identify the primes: 2, 3, 5, 7 are the smallest four primes. Then add them explicitly. Writing the list prevents the common error of including 1 or skipping 7 by mistake. Ensuring fundamental definitions avoids traps in multiple-choice settings.

Step-by-Step Solution:List primes: 2, 3, 5, 7.Add: 2 + 3 = 5.Add next: 5 + 5 = 10.Add last: 10 + 7 = 17.

Verification / Alternative check:Double-check primality: each of 2, 3, 5, 7 has no positive divisors other than 1 and itself. Re-sum quickly to confirm 17.

Why Other Options Are Wrong:

• 10 / 11 / 16 / 19: Each corresponds to a mis-addition or an incorrect set of early primes (for example, accidentally including 1 or omitting 7).

Common Pitfalls:Counting 1 as a prime; forgetting that 2 is prime; adding too fast and arriving at 16 instead of 17.

Final Answer:17