Mathematics/General Ability MCQs
Topic Notes: Mathematics/General Ability
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
51
A tank is filled by two pipes in 17 min and 21 min respectively, and drained by a third pipe in 33 min. How long to fill the tank if all operate together?
Answer:
13.13
Step-by-step solution: 1. Filling rates: 1/17 + 1/21. 2. Draining rate: 1/33. 3. Net rate = 1/17 + 1/21 - 1/33 = 0.0761 tank/min. 4. Time = 1 / net rate = 13.13 minutes.
52
A tank is filled by two pipes in 20 min and 20 min respectively, and drained by a third pipe in 30 min. How long to fill the tank if all operate together?
Answer:
15.0
Step-by-step solution: 1. Filling rates: 1/20 + 1/20. 2. Draining rate: 1/30. 3. Net rate = 1/20 + 1/20 - 1/30 = 0.0667 tank/min. 4. Time = 1 / net rate = 15.0 minutes.
53
A tank is filled by two pipes in 19 min and 22 min respectively, and drained by a third pipe in 31 min. How long to fill the tank if all operate together?
Answer:
15.19
Step-by-step solution: 1. Filling rates: 1/19 + 1/22. 2. Draining rate: 1/31. 3. Net rate = 1/19 + 1/22 - 1/31 = 0.0658 tank/min. 4. Time = 1 / net rate = 15.19 minutes.
54
A tank is filled by two pipes in 18 min and 24 min respectively, and drained by a third pipe in 34 min. How long to fill the tank if all operate together?
Answer:
14.75
Step-by-step solution: 1. Filling rates: 1/18 + 1/24. 2. Draining rate: 1/34. 3. Net rate = 1/18 + 1/24 - 1/34 = 0.0678 tank/min. 4. Time = 1 / net rate = 14.75 minutes.
55
A tank is filled by two pipes in 19 min and 26 min respectively, and drained by a third pipe in 30 min. How long to fill the tank if all operate together?
Answer:
17.31
Step-by-step solution: 1. Filling rates: 1/19 + 1/26. 2. Draining rate: 1/30. 3. Net rate = 1/19 + 1/26 - 1/30 = 0.0578 tank/min. 4. Time = 1 / net rate = 17.31 minutes.
56
A tank is filled by two pipes in 16 min and 22 min respectively, and drained by a third pipe in 32 min. How long to fill the tank if all operate together?
Answer:
13.04
Step-by-step solution: 1. Filling rates: 1/16 + 1/22. 2. Draining rate: 1/32. 3. Net rate = 1/16 + 1/22 - 1/32 = 0.0767 tank/min. 4. Time = 1 / net rate = 13.04 minutes.
57
A tank is filled by two pipes in 16 min and 26 min respectively, and drained by a third pipe in 34 min. How long to fill the tank if all operate together?
Answer:
13.98
Step-by-step solution: 1. Filling rates: 1/16 + 1/26. 2. Draining rate: 1/34. 3. Net rate = 1/16 + 1/26 - 1/34 = 0.0715 tank/min. 4. Time = 1 / net rate = 13.98 minutes.
58
A tank is filled by two pipes in 19 min and 20 min respectively, and drained by a third pipe in 33 min. How long to fill the tank if all operate together?
Answer:
13.83
Step-by-step solution: 1. Filling rates: 1/19 + 1/20. 2. Draining rate: 1/33. 3. Net rate = 1/19 + 1/20 - 1/33 = 0.0723 tank/min. 4. Time = 1 / net rate = 13.83 minutes.
59
A tank is filled by two pipes in 18 min and 23 min respectively, and drained by a third pipe in 31 min. How long to fill the tank if all operate together?
Answer:
14.98
Step-by-step solution: 1. Filling rates: 1/18 + 1/23. 2. Draining rate: 1/31. 3. Net rate = 1/18 + 1/23 - 1/31 = 0.0668 tank/min. 4. Time = 1 / net rate = 14.98 minutes.
60
A tank is filled by two pipes in 20 min and 20 min respectively, and drained by a third pipe in 34 min. How long to fill the tank if all operate together?
Answer:
14.17
Step-by-step solution: 1. Filling rates: 1/20 + 1/20. 2. Draining rate: 1/34. 3. Net rate = 1/20 + 1/20 - 1/34 = 0.0706 tank/min. 4. Time = 1 / net rate = 14.17 minutes.