All Categories MCQs
Topic Notes: All Categories
General Description
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
7181
A is 2 years older than B who is twice as old as C. If the total of the ages of A, B and C be 27, then how old is B?
Answer:
10
Let C's age be x. Then B's age is 2x, and A's age is 2x + 2. Total age = x + 2x + (2x + 2) = 27. 5x + 2 = 27 => 5x = 25 => x = 5. B's age is 2x = 2 * 5 = 10 years.
7182
The ratio of the present ages of two brothers is 1 : 2. 5 years back, the ratio was 1 : 3. What will be the ratio of their ages after 5 years?
Answer:
3 : 5
Let present ages be x and 2x. 5 years ago: (x - 5) / (2x - 5) = 1 / 3. Cross-multiplying: 3x - 15 = 2x - 5 => x = 10. Present ages are 10 and 20. After 5 years, ages will be 15 and 25. Ratio is 15 : 25 = 3 : 5.
7183
A sum of money is divided into two parts in the ratio 5:6. If the second part is 120, what is the total sum?
Answer:
220
Second part = 6 parts = 120 => 1 part = 20. Total parts = 11. Total sum = 11 * 20 = 220.
7184
In a regular polygon, the ratio of interior angle to exterior angle is 3:1. The number of sides is:
Answer:
8
Sum of interior and exterior angle = 180. 3x + x = 180 => 4x = 180 => x = 45. Exterior angle = 45. Number of sides = 360 / Exterior angle = 360 / 45 = 8.
7185
Divide Rs 1000 in the ratio 3:7. The larger part is:
Answer:
700
Total parts = 3 + 7 = 10. Value of 1 part = 1000 / 10 = 100. Larger part = 7 * 100 = 700.
7186
The ratio of the length of a school ground to its width is 5:2. If the width is 40m, then the length is:
Answer:
100 m
Length/Width = 5/2. Length/40 = 5/2. Length = (5*40)/2 = 100 m.
7187
If an alloy contains copper and tin in the ratio 3:2, and it contains 12 kg of copper, what is the weight of tin?
Answer:
8 kg
Copper = 3 parts = 12 kg. 1 part = 4 kg. Tin = 2 parts = 2 * 4 = 8 kg.
7188
Find the third proportional to 4 and 12.
Answer:
36
4 : 12 = 12 : x. Product of extremes = Product of means. 4x = 144 => x = 36.
7189
The ages of Ram and Shyam are in the ratio 5:7. If the sum of their ages is 48 years, what is the age of Shyam?
Answer:
28
5x + 7x = 48 => 12x = 48 => x = 4. Shyam's age = 7x = 7 * 4 = 28 years.
7190
A proportion states that two ratios are:
Answer:
Equal
A proportion is a mathematical statement or equation that shows two ratios are equal (e.g., a/b = c/d).