Basic Probability and Fractions: TEAS Practice Question with Answer & Explanation

Understanding the Concept: Basic Probability

Probability is a measure of how likely an event is to occur. On the TEAS 7 Math section, you are frequently asked to calculate the probability of a single, random event. To solve these problems, you use the fundamental probability formula:

Probability = (Number of Desired Outcomes) / (Total Number of Possible Outcomes)

Step-by-Step Breakdown

1. Find the Total Number of Outcomes First, you must determine the total number of items in the set. In this scenario, we add all the bandages together:

• 15 (Dinosaur) + 12 (Superhero) + 6 (Glitter) + 4 (Animal Print) + 3 (Plain) = 40 total bandages.

2. Identify the Desired Outcome The question asks for the probability of selecting a glitter bandage. Looking back at the data provided:

• There are 6 glitter bandages.

3. Set Up the Fraction Place the number of glitter bandages over the total number of bandages:

• Probability = 6 / 40

4. Simplify the Fraction Most TEAS questions will require you to simplify the fraction to its lowest terms. To simplify 6/40, find the Greatest Common Factor (GCF) that goes into both 6 and 40.

• Both numbers are even, so they are divisible by 2.
• 6 ÷ 2 = 3
• 40 ÷ 2 = 20
• The simplified fraction is 3/20. Wait—looking at the options, we must ensure we calculated correctly. Let's re-add: 15+12+6+4+3. 15+12=27. 27+6=33. 33+4=37. 37+3=40. Correct. 6/40 simplifies to 3/20.

Wait! Let's re-check the calculation.

• 15 + 12 = 27
• 27 + 6 = 33
• 33 + 4 = 37
• 37 + 3 = 40.
• 6 / 40 simplifies by dividing by 2 to get 3 / 20.

Explanation of Distractors

• A) 3/20: This is the correct simplified form of 6/40.
• B) 1/8: This would be the answer if there were 5 glitter bandages (5/40 = 1/8).
• C) 3/100: This is a decimal-placement error, confusing the fraction with a percentage (3%).
• D) 3/40: This occurs if you forget to simplify correctly or only divide the numerator by 2 but not the denominator.

TEAS Nursing Tip

When you see a word problem like this, always underline the specific item requested (e.g., "glitter") so you don't accidentally calculate the probability for the wrong category (like "dinosaur" or "plain").