ASVAB Arithmetic Reasoning Practice Test 2026 – Complete Exam Prep

To determine the probability of selecting either a red or a black pen from the backpack, we first need to establish the total number of pens in the backpack.

The backpack contains:

- 5 blue pens

- 6 black pens

- 4 red pens

Calculating the total number of pens involves adding all the pens together:

5 (blue) + 6 (black) + 4 (red) = 15 pens in total.

Next, we want to find out how many pens are either red or black. We have:

- 6 black pens

- 4 red pens

Adding these together gives:

6 (black) + 4 (red) = 10 pens that are either black or red.

The probability of drawing a pen that is either red or black is the number of successful outcomes (drawing a black or red pen) divided by the total number of possible outcomes (the total number of pens).

Thus, the probability can be calculated as follows:

Probability = Number of favorable outcomes / Total number of outcomes = 10 / 15.

This fraction can be simplified:

10 / 15 = 2 / 3.

Therefore, the correct answer is indeed 2/3, as it accurately