2 IS THE ONLY EVEN PRIME NUMBER a prime number can only be divided by 1 or itself. 4 is a composite and 5 is a prime hope this helps you.
Hey I tried, hope it helps... can't work it out, all the best
Answer:

Step-by-step explanation:
we know that
The <u><em>Triangle Inequality Theorem</em></u> states that the sum of any 2 sides of a triangle must be greater than the measure of the third side
so
Applying the Triangle Inequality Theorem
1) 
solve for n

Rewrite

2) 

therefore

Answer: The required number of books that Ruben had before purchases is 50.
Step-by-step explanation: Given that Ruben bought 6 new books for his collection that increased his collection by 12%.
We are to find the number of books that Ruben had before purchases.
Let x denotes the number of books that Ruben had before purchases.
Then, according to the given information, we have

Thus, the required number of books that Ruben had before purchases is 50.