GSA Practice Set 3 – General Science & Ability (20 Original MCQs Explained)

This is GSA Practice Set 3 — 20 original MCQs for General Science & Ability (CSS Compulsory, 100 marks). 10 Science (Q1–Q10) + 10 Ability (Q11–Q20). Attempt all 20 in 25 minutes without looking at the answers, then check the explained answers. These are original practice questions, not copied from FPSC papers or competitor question banks, and this site is not affiliated with FPSC. Scoring: 18–20 = strong. 15–17 = good. 12–14 = fair, revise the ones you missed. Below 12 = study the weak-section review, then re-attempt in 2 days.

Science (Q1–Q10)

Q1. H2O is the chemical formula for: A) Salt B) Water C) Oxygen D) Carbon dioxide

Q2. Which gas is commonly used to fill balloons (lighter than air)? A) Oxygen B) Helium C) Carbon dioxide D) Nitrogen

Q3. Which vitamin is produced in human skin by sunlight? A) Vitamin A B) Vitamin B C) Vitamin C D) Vitamin D

Q4. What is the chemical symbol for gold? A) Ag B) Au C) Fe D) Pb

Q5. Which organ pumps blood around the human body? A) Liver B) Lung C) Heart D) Kidney

Q6. Which planet is nearest to the Sun? A) Venus B) Earth C) Mercury D) Mars

Q7. Which is the largest planet in the solar system? A) Saturn B) Jupiter C) Neptune D) Uranus

Q8. What is the approximate speed of light in a vacuum? A) 300 km/s B) 3,000 km/s C) 300,000 km/s D) 3,000,000 km/s

Q9. Which acid is found in vinegar? A) Citric acid B) Acetic acid C) Hydrochloric acid D) Sulphuric acid

Q10. Which organelle is called the powerhouse of the cell? A) Nucleus B) Ribosome C) Mitochondria D) Golgi body

Ability (Q11–Q20)

Q11. If a train travels 60 km in 1 hour, how far will it travel in 3 hours (same speed)? A) 120 km B) 150 km C) 180 km D) 200 km

Q12. What is 25% of 200? A) 25 B) 40 C) 50 D) 75

Q13. If 5x = 35, what is x? A) 5 B) 6 C) 7 D) 8

Q14. Next number in the series: 3, 6, 12, 24, ? A) 36 B) 42 C) 48 D) 60

Q15. A rectangle has length 10 cm and width 5 cm. What is its area? A) 15 sq cm B) 25 sq cm C) 50 sq cm D) 100 sq cm

Q16. Which of these is an even number? A) 33 B) 41 C) 42 D) 45

Q17. If a : b = 2 : 3 and a = 10, what is b? A) 12 B) 15 C) 18 D) 20

Q18. Which of these is a prime number? A) 15 B) 18 C) 17 D) 21

Q19. What is the average of 10, 20, and 30? A) 15 B) 20 C) 25 D) 30

Q20. If a car travels 100 km in 2 hours, what is its speed? A) 25 km/h B) 40 km/h C) 50 km/h D) 100 km/h

Answer Key + Explained Answers

Q1 – B) Water. H2O is water (2 hydrogen, 1 oxygen). Salt = NaCl, Oxygen = O2, Carbon dioxide = CO2.

Q2 – B) Helium. Helium is lighter than air and used in balloons. Oxygen and nitrogen are not lighter than air in the same way; CO2 is heavier.

Q3 – D) Vitamin D. Vitamin D is produced in skin by sunlight (UV). Vitamin A is from food (carrots); B and C are from food.

Q4 – B) Au. Gold = Au (from Latin Aurum). Ag = silver, Fe = iron, Pb = lead.

Q5 – C) Heart. The heart pumps blood. Liver = detox, Lung = breathing, Kidney = filtration.

Q6 – C) Mercury. Mercury is nearest to the Sun. Venus is second, Earth third, Mars fourth.

Q7 – B) Jupiter. Jupiter is the largest planet. Saturn is second largest (with rings); Neptune and Uranus are smaller.

Q8 – C) 300,000 km/s. Speed of light in vacuum ≈ 300,000 km/s (299,792 km/s). 300 and 3,000 are far too low; 3,000,000 is too high.

Q9 – B) Acetic acid. Vinegar contains acetic acid (CH3COOH). Citric = citrus fruits, Hydrochloric = stomach acid, Sulphuric = industrial acid.

Q10 – C) Mitochondria. Mitochondria produce energy (ATP) — powerhouse of the cell. Nucleus = control, Ribosome = protein synthesis, Golgi = packaging.

Q11 – C) 180 km. Distance = speed × time = 60 × 3 = 180 km.

Q12 – C) 50. 25% of 200 = 0.25 × 200 = 50.

Q13 – C) 7. 5x = 35 → x = 35 ÷ 5 = 7.

Q14 – C) 48. Each term doubles: 3 × 2 = 6, 6 × 2 = 12, 12 × 2 = 24, 24 × 2 = 48.

Q15 – C) 50 sq cm. Area = length × width = 10 × 5 = 50 sq cm.

Q16 – C) 42. Even numbers are divisible by 2. 42 ÷ 2 = 21. 33, 41, 45 are odd.

Q17 – B) 15. a : b = 2 : 3 means b = (3/2) × a = 1.5 × 10 = 15.

Q18 – C) 17. Prime = only factors 1 and itself. 17 is prime. 15 = 3 × 5, 18 = 2 × 9, 21 = 3 × 7.

Q19 – B) 20. Average = (10 + 20 + 30) ÷ 3 = 60 ÷ 3 = 20.

Q20 – C) 50 km/h. Speed = distance ÷ time = 100 ÷ 2 = 50 km/h.

Weak-Section Review

Which section did you score lowest in? Write the 3 questions you missed, the correct answers, and one line for each explaining why. Science: revise symbols (Au, Ag, Fe, Pb), planets (Mercury nearest, Jupiter largest), vitamins (D = sunlight), cell (mitochondria), acids (acetic = vinegar). Ability: revise percentages, ratios, averages, speed = distance ÷ time, area = length × width, primes vs even. Re-attempt this set in 2 days.

These are original practice questions written for csspastpapers.pk. They are not FPSC official questions, and this site is not affiliated with FPSC.

Related: GSA Past Papers | CSS Syllabus | GSA Practice Set 1 | GSA Practice Set 2 | MPT Practice Set 1