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
61
A tank is filled by two pipes in 17 min and 24 min respectively, and drained by a third pipe in 33 min. How long to fill the tank if all operate together?
Answer:
14.25
Step-by-step solution: 1. Filling rates: 1/17 + 1/24. 2. Draining rate: 1/33. 3. Net rate = 1/17 + 1/24 - 1/33 = 0.0702 tank/min. 4. Time = 1 / net rate = 14.25 minutes.
62
A tank is filled by two pipes in 20 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:
14.86
Step-by-step solution: 1. Filling rates: 1/20 + 1/21. 2. Draining rate: 1/33. 3. Net rate = 1/20 + 1/21 - 1/33 = 0.0673 tank/min. 4. Time = 1 / net rate = 14.86 minutes.
63
A tank is filled by two pipes in 20 min and 23 min respectively, and drained by a third pipe in 33 min. How long to fill the tank if all operate together?
Answer:
15.83
Step-by-step solution: 1. Filling rates: 1/20 + 1/23. 2. Draining rate: 1/33. 3. Net rate = 1/20 + 1/23 - 1/33 = 0.0632 tank/min. 4. Time = 1 / net rate = 15.83 minutes.
64
A tank is filled by two pipes in 15 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:
11.91
Step-by-step solution: 1. Filling rates: 1/15 + 1/21. 2. Draining rate: 1/33. 3. Net rate = 1/15 + 1/21 - 1/33 = 0.0840 tank/min. 4. Time = 1 / net rate = 11.91 minutes.
65
A tank is filled by two pipes in 15 min and 22 min respectively, and drained by a third pipe in 34 min. How long to fill the tank if all operate together?
Answer:
12.09
Step-by-step solution: 1. Filling rates: 1/15 + 1/22. 2. Draining rate: 1/34. 3. Net rate = 1/15 + 1/22 - 1/34 = 0.0827 tank/min. 4. Time = 1 / net rate = 12.09 minutes.
66
A tank is filled by two pipes in 18 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:
13.29
Step-by-step solution: 1. Filling rates: 1/18 + 1/20. 2. Draining rate: 1/33. 3. Net rate = 1/18 + 1/20 - 1/33 = 0.0753 tank/min. 4. Time = 1 / net rate = 13.29 minutes.
67
A tank is filled by two pipes in 17 min and 21 min respectively, and drained by a third pipe in 30 min. How long to fill the tank if all operate together?
Answer:
13.68
Step-by-step solution: 1. Filling rates: 1/17 + 1/21. 2. Draining rate: 1/30. 3. Net rate = 1/17 + 1/21 - 1/30 = 0.0731 tank/min. 4. Time = 1 / net rate = 13.68 minutes.
68
A tank is filled by two pipes in 15 min and 23 min respectively, and drained by a third pipe in 30 min. How long to fill the tank if all operate together?
Answer:
13.02
Step-by-step solution: 1. Filling rates: 1/15 + 1/23. 2. Draining rate: 1/30. 3. Net rate = 1/15 + 1/23 - 1/30 = 0.0768 tank/min. 4. Time = 1 / net rate = 13.02 minutes.
69
A tank is filled by two pipes in 17 min and 21 min respectively, and drained by a third pipe in 32 min. How long to fill the tank if all operate together?
Answer:
13.3
Step-by-step solution: 1. Filling rates: 1/17 + 1/21. 2. Draining rate: 1/32. 3. Net rate = 1/17 + 1/21 - 1/32 = 0.0752 tank/min. 4. Time = 1 / net rate = 13.3 minutes.
70
A tank is filled by two pipes in 15 min and 26 min respectively, and drained by a third pipe in 31 min. How long to fill the tank if all operate together?
Answer:
13.72
Step-by-step solution: 1. Filling rates: 1/15 + 1/26. 2. Draining rate: 1/31. 3. Net rate = 1/15 + 1/26 - 1/31 = 0.0729 tank/min. 4. Time = 1 / net rate = 13.72 minutes.