GED Mathematical Reasoning TestQuantitative Problem Solving with Rational NumbersEasy
A recipe for muffins calls for 1 1/2 cups of flour. If a baker wants to make 2/3 of the recipe, how much flour should they use?
- A2 1/4 cups
- B1 cup
- C1/2 cup
- D1 1/3 cups
Show answer & explanationAnswer & explanation
Correct answer: B. 1 cup
To find out how much flour is needed, multiply the original amount of flour by the fraction of the recipe being made. Convert the mixed number to an improper fraction first, then multiply.
Why the other options are wrong
- A. This would be the result if the original recipe was multiplied by 1 1/2 instead of 2/3.
- C. This would be the result if 1 1/2 was incorrectly multiplied by 1/3.
- D. This would be the result if 2/3 was added to 1 1/2 instead of multiplied.
Multiplying Mixed Numbers
To multiply a mixed number by a fraction, first convert the mixed number into an improper fraction. Then, multiply the numerators and multiply the denominators.
- Convert mixed numbers to improper fractions before multiplying.
- Multiply numerators together.
- Multiply denominators together.
- Simplify the resulting fraction if possible.
Memory trick: Mixed fractions must be 'improper' before you multiply them properly!