Review Comments of Math Practice Questions Air Class
Question 1:
Answer: 28000
Steps:
- Correctly calculated 20% profit on 50 laptops: 4800 - 4000 = 800 profit per laptop.
- Correctly calculated total profit for 50 laptops: 800 × 50 = 40000.
- Correctly calculated 75% of selling price for remaining 30 laptops: 3600.
- Correctly calculated loss per laptop: 3600 - 4000 = -400.
- Correctly calculated total loss for 30 laptops: -400 × 30 = -12000.
- Correctly added profits and losses: 40000 + (-12000) = 28000.
Feedback: Well done! All steps and the final answer are correct.
Question 2:
Answer: C=1000
Steps:
- Correctly set up the equations: MP = 1.2C, SP = 0.8MP.
- Correctly substituted and simplified: C - 0.96C = 40.
- Correctly solved for C: 0.04C = 40 → C = 1000.
Feedback: Excellent work! The steps and final answer are correct.
Question 3:
Answer: The shopkeeper did not profit; the net result was zero.
Steps:
- Correctly identified that the profit and loss cancel each other out.
Feedback: Correct! The net profit is zero.
Question 4:
Answer: After 3 years of simple interest he will earn $192 and it will take him 8 years to earn 512 dollars of interest.
Steps:
- Correctly calculated yearly interest: 8% of 800 = 64.
- Correctly calculated total interest for 3 years: 64 × 3 = 192.
- Correctly calculated time to earn 512: 512 / 64 = 8 years.
Feedback: Perfect! All steps and answers are correct.
Question 5:
Answer: $530.45
Steps:
- Correctly calculated first year interest: 3% of 500 = 15 → 515.
- Correctly calculated second year interest: 3% of 515 = 15.45 → 530.45.
Feedback: Great job! The steps and final answer are correct.
Overall Score: 10