A shopkeeper in Anarkali Bazaar buys 50 kg of rice at Rs. 120 per kg and 30 kg of rice at Rs. 150 per kg. If he mixes them and sells the mixture at Rs. 140 per kg, what is his total profit?
Options: A: Rs. 400, B: Rs. 600, C: Rs. 800, D: Rs. 1,000, E: None of the above
Correct Answer: C
Explanation: Total cost = (50 * 120) + (30 * 150) = 6000 + 4500 = Rs. 10,500. Total weight = 80 kg; Total revenue = 80 * 140 = Rs. 11,200. Profit = 11,200 - 10,500 = Rs. 700. Since 700 is not listed, E is the correct choice. CSS examiners often include 'None of the above' to test calculation accuracy.
What is the smallest prime number that is also an odd number?
Options: A: 1, B: 2, C: 3, D: 5
Correct Answer: C
Explanation: By definition, 1 is not a prime number. 2 is the only even prime number. Therefore, 3 is the smallest odd prime number. Students often mistakenly pick 1 or 2 due to confusion regarding prime number definitions.
If the price of petrol in Pakistan increases by 20%, by what percentage must a car owner reduce consumption to keep the total expenditure on petrol constant?
Options: A: 15.67%, B: 16.67%, C: 20%, D: 25%, E: 18.33%
Correct Answer: B
Explanation: Let initial price be 100 and consumption be 100. Expenditure = 10,000. New price = 120. To keep expenditure at 10,000, new consumption = 10,000 / 120 = 83.33. Reduction = 100 - 83.33 = 16.67%. This is a classic FPSC percentage application question.
A train 150 meters long is running at a speed of 54 km/hr. How much time will it take to cross a platform 250 meters long?
Options: A: 20 seconds, B: 25 seconds, C: 30 seconds, D: 35 seconds, E: 40 seconds
Correct Answer: B
Explanation: Total distance = 150 + 250 = 400 meters. Speed = 54 km/hr = 54 * (5/18) = 15 m/s. Time = Distance / Speed = 400 / 15 = 26.66 seconds. Since 26.66 is not in options, E is correct. A common trap is forgetting to convert km/hr to m/s.
The average age of 5 members of a family in Lahore is 30 years. If the age of the youngest member (aged 10) is excluded, what is the new average age of the remaining family members?
Options: A: 32 years, B: 35 years, C: 37.5 years, D: 40 years, E: None of the above
Correct Answer: B
Explanation: Total age = 5 * 30 = 150. After excluding 10, total age = 140. New average = 140 / 4 = 35. This tests basic arithmetic mean properties frequently found in NTS and PPSC papers.
Which of the following fractions is the largest?
Options: A: 5/8, B: 7/12, C: 9/16, D: 11/20, E: 13/24
Correct Answer: A
Explanation: Convert to decimals: 5/8 = 0.625, 7/12 = 0.583, 9/16 = 0.5625, 11/20 = 0.55, 13/24 = 0.541. Comparing these, 0.625 is the largest. Converting to a common denominator is another valid strategy for these exams.
If 15 workers can build a wall in 20 days, how many days will 25 workers take to build the same wall?
Options: A: 10 days, B: 12 days, C: 14 days, D: 15 days, E: 18 days
Correct Answer: B
Explanation: This is an inverse proportion problem: M1*D1 = M2*D2. 15 * 20 = 25 * D2. 300 = 25 * D2. D2 = 300 / 25 = 12. Students often confuse direct and inverse proportions, leading to incorrect answers like 33.3.
What is the simple interest on Rs. 20,000 at a rate of 10% per annum for 3 years?
Options: A: Rs. 2,000, B: Rs. 4,000, C: Rs. 6,000, D: Rs. 8,000, E: Rs. 10,000
Correct Answer: C
Explanation: Simple Interest formula is (P * R * T) / 100. (20,000 * 10 * 3) / 100 = 6,000. This is a fundamental formula tested in almost every competitive exam in Pakistan.
A sum of money doubles itself in 5 years at simple interest. In how many years will it become 4 times itself?
Options: A: 10 years, B: 12 years, C: 15 years, D: 20 years, E: 25 years
Correct Answer: C
Explanation: If it doubles in 5 years, the interest earned is equal to the principal in 5 years. To become 4 times, the interest must be 3 times the principal. Therefore, it will take 5 * 3 = 15 years. This is a high-level logic question often used in CSS screening tests.
The ratio of boys to girls in a school is 3:2. If there are 600 students in total, how many girls are there?
Options: A: 200, B: 240, C: 300, D: 360, E: 400
Correct Answer: B
Explanation: Total parts = 3 + 2 = 5. Value of one part = 600 / 5 = 120. Number of girls = 2 parts = 2 * 120 = 240. A common error is calculating for boys (360) instead of girls.