Praxis Core Academic Skills for Educators: Mathematics (5733)Number and QuantityMedium
A quality control specialist is inspecting a batch of microchips. Out of 200 chips, 3% are found to be defective. How many microchips are defective?
- A20
- B10
- C6
- D3
Show answer & explanationAnswer & explanation
Correct answer: C. 6
To find the number of defective chips, convert the percentage to a decimal (3% = 0.03) and then multiply it by the total number of chips.
Why the other options are wrong
- A. This would be 10% of 200.
- B. This would be 5% of 200.
- D. This would be 1.5% of 200.
Percent of a Number
To find the percent of a number, convert the percentage to a decimal by dividing by 100, then multiply that decimal by the given number.
- Percent means 'per hundred' or 'out of 100'.
- To convert a percent to a decimal, divide by 100 (move decimal two places left).
- The word 'of' in math problems often indicates multiplication.
Memory trick: Percent to decimal, then multiply the whole.