Praxis Core Academic Skills for Educators: Mathematics (5733)Number and QuantityEasy

A quality control technician inspects a batch of 480 electronic components. If 1/16 of the components are found to be defective, how many components are NOT defective?

  1. A456
  2. B30
  3. C450
  4. D464
Show answer & explanation

Correct answer: A. 456

First, calculate the number of defective components. Then subtract that number from the total to find the non-defective components.

Why the other options are wrong

  • B. This is the number of defective components, not non-defective.
  • C. This would be correct if 1/10 of the components were defective, not 1/16.
  • D. This is an incorrect calculation; it would result from subtracting 16 from 480, not 1/16 of 480.

Fractions of a Whole

To find a fraction of a whole number, multiply the fraction by the whole number. To find the remainder, subtract this result from the whole.

  • Represents a part of a total.
  • Numerator is the part, denominator is the whole.
  • Can be used to calculate specific quantities within a larger group.

Memory trick: Slice the whole, then count what's left.

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