Mathematics Class 10 - Percentage Quiz

Study Notes

Percentage Calculations

Problem 1: Equation derived from percentages
- Formula: (18% of 250 + 25% of 144) of ? = 54
- Breakdown:
  - 18% of 250 = 45
  - 25% of 144 = 36
  - Total = 45 + 36 = 81
  - Therefore, 81% of ? = 54
  - Solve for ?: ? = 54 / 0.81 = 66.67 (approximately)

Additional Percentage Problems

Problem 2: Calculate the product of two percentages
- Question: 36% of 4800 x 0.2% of 1320
- Steps:
  - 36% of 4800 = 1728
  - 0.2% of 1320 = 2.64
  - Final answer: 1728 x 2.64 = 4561.92

Finding Percent Values

Problem 3: Determine percentage from given values
- Solve: ?% of 35568 = 650
- Rearranging gives: ? = (650 / 35568) x 100
- Calculated percentage:
  - ? ≈ 1.83%

Multiple Choice Options

Multiple choice options provided for each problem
- For the first problem, options include variables and undefined values
- Second problem results with options close to calculated value (answer c: 4561.92)
- Third problem offers options ranging from 12% to 18%, none closely representing calculated 1.83%.

Key Concepts

Understanding how to manipulate and derive equations from percentage problems aids in solving complex calculations efficiently.
Recognizing the relationships between part, whole, and percentage is vital for quick problem-solving in mathematics.

College Election Votes

One candidate received 55% of total valid votes in the election.
15% of the total votes were invalid.
Total votes cast in the election: 15,200.
To find valid votes:
- Invalid votes = 15% of 15,200 = 2,280.
- Valid votes = Total votes - Invalid votes = 15,200 - 2,280 = 12,920.
Votes for the first candidate (55% of valid votes) = 55% of 12,920 = 7,096.
Votes for the other candidate = Valid votes - Votes for the first candidate = 12,920 - 7,096 = 5,824.
Thus, the other candidate got 5,824 valid votes.

Percentage Calculation

15% of 45% of a number equals 105.3.
To find the unknown number (let's call it x):
- 15% of 45% = 0.15 * 0.45 = 0.0675.
- Therefore, 0.0675 * x = 105.3.
- Solving for x gives x = 105.3 / 0.0675 = 1,560.
To find 24% of this number (1,560):
- 24% of 1,560 = 0.24 * 1,560 = 374.4.

Exam Performance

Jassi answered 40% of the first 125 questions correctly.
Total number of questions: 250.
To achieve a 60% overall grade on the exam:
- Total correct answers needed = 60% of 250 = 150.
Correct answers from the first half (125 questions):
- 40% of 125 = 50.
Remaining correct answers needed from the second half:
- 150 - 50 = 100.
Percent needed from the other 125 questions:
- To find percentage: (100 / 125) * 100 = 80%.

Summary of Answer Options

College election valid votes: 5,824 for the other candidate.
Number calculation result for the unknown number is 1,560, and 24% of that is 374.4.
Jassi needs to answer 80% of the remaining questions correctly to achieve a 60% overall grade.

Description

Test your knowledge of percentages with this quiz featuring various problems related to percentage calculations. Suitable for 10th-grade students, this quiz covers practical applications of percentages in real-world scenarios.