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
201
Rs. 33630 are divided among A, B, and C in such a manner that the ratio of the amount of A to that of B is 3:7 and the ratio of the amount of B to that of C is 6:5. The amount of money received by B is:
Answer:
Rs. 14868
A:B = 3:7 = 18:42. B:C = 6:5 = 42:35. Ratio A:B:C = 18:42:35. Total parts = 18+42+35 = 95. B's share = (42/95) * 33630 = 42 * 354 = Rs. 14868.
202
Two numbers are in the ratio 1 : 2. If 7 is added to both, their ratio changes to 3 : 5. The greatest number is:
Answer:
28
Let numbers be x and 2x. (x + 7) / (2x + 7) = 3 / 5. Cross-multiply: 5x + 35 = 6x + 21 => x = 14. Greatest number is 2x = 28.
203
A and B together have Rs. 1210. If 4/15 of A's amount is equal to 2/5 of B's amount, how much does B have?
Answer:
Rs. 484
(4/15)A = (2/5)B => A/B = (2/5) * (15/4) = 30/20 = 3/2. Ratio A:B = 3:2. Total parts = 5. B's share = (2/5) * 1210 = Rs. 484.
204
If 15% of m = 20% of n, then m : n is:
Answer:
4 : 3
15m = 20n. Therefore, m/n = 20/15 = 4/3. So, m : n = 4 : 3.
205
Divide 1162 among A, B, C in the ratio 35 : 28 : 20. Find C's share.
Answer:
Rs. 280
Total parts = 35 + 28 + 20 = 83. Value of 1 part = 1162 / 83 = 14. C's share = 20 * 14 = Rs. 280.
206
If a : b = 5 : 9 and b : c = 4 : 7, find a : b : c.
Answer:
20 : 36 : 63
To make 'b' common in both ratios, multiply a:b by 4 and b:c by 9. a:b = 20:36 and b:c = 36:63. The combined ratio a:b:c is 20:36:63.
207
The mean proportional between 0.02 and 0.32 is:
Answer:
0.08
Mean proportional = sqrt(0.02 * 0.32) = sqrt(0.0064) = 0.08.
208
Find the third proportional to 9 and 12.
Answer:
16
Let the third proportional be x. 9 : 12 = 12 : x. 9x = 144, so x = 16.
209
The fourth proportional to 5, 8, 15 is:
Answer:
24
Let the fourth proportional be x. 5 : 8 = 15 : x. 5x = 120, so x = 24.
210
The ratio of 25 minutes to 1 hour is:
Answer:
5 : 12
To find the ratio, both quantities must be in the same unit. 1 hour = 60 minutes. The ratio is 25 : 60. Dividing both terms by 5 gives 5 : 12.