GED Mathematical Reasoning TestQuantitative Problem Solving with Rational NumbersEasy
A survey of 500 people found that 60% prefer coffee, 25% prefer tea, and the rest prefer hot chocolate. How many people prefer hot chocolate?
- A125
- B50
- C75
- D100
Show answer & explanationAnswer & explanation
Correct answer: C. 75
First, find the total percentage of people who prefer coffee or tea: 60% + 25% = 85%. Then, find the percentage who prefer hot chocolate: 100% - 85% = 15%. Finally, calculate 15% of the total 500 people: 0.15 * 500 = 75 people.
Why the other options are wrong
- A. This is 25% of 500, which is the number who prefer tea.
- B. This is 10% of 500.
- D. This is 20% of 500.
Percentages of a Whole
The sum of all percentages representing parts of a whole must equal 100%. To find an unknown part, subtract known parts (as percentages) from 100%, then calculate that percentage of the total.
- Total percentage = 100%.
- Convert percentages to decimals for calculations (divide by 100).
- Multiply decimal percentage by the total number to find the count for that part.
Memory trick: All parts add to 100, subtract what you know, the rest is found, then multiply slow.