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
7211
Ratio of earnings of A and B is 4:7. If the earnings of A increase by 50% and those of B decrease by 25%, the new ratio of their earnings becomes 8:7. What is A's earning?
Answer:
Data inadequate
Let earnings be 4x and 7x. New earnings: A = 4x * 1.5 = 6x. B = 7x * 0.75 = 5.25x. Ratio = 6x / 5.25x = 600 / 525 = 8 / 7. This identity holds true regardless of x, so the actual earnings cannot be determined from this information alone.
7212
In a school, the ratio of boys to girls is 4:3 and the ratio of girls to teachers is 8:1. What is the ratio of students to teachers?
Answer:
56:3
Boys:Girls = 4:3 = 32:24. Girls:Teachers = 8:1 = 24:3. Boys:Girls:Teachers = 32:24:3. Total students = 32+24=56. Students:Teachers = 56:3.
7213
A fraction bears the same ratio to 1/27 as 3/7 does to 5/9. The fraction is:
Answer:
1/35
Let fraction be x. x : 1/27 = 3/7 : 5/9. x / (1/27) = (3/7) / (5/9) => 27x = 27/35. x = 1/35.
7214
If a/2 = b/3 = c/5, find (a+b+c)/c.
Answer:
2
Let a/2 = b/3 = c/5 = k. a=2k, b=3k, c=5k. (a+b+c)/c = (2k+3k+5k)/5k = 10k/5k = 2.
7215
A bag contains Rs 410 in the form of Rs 5, Rs 2, and Rs 1 coins in the ratio 4:6:9. The number of Rs 2 coins is:
Answer:
60
Coins ratio 4x, 6x, 9x. Value = 5(4x) + 2(6x) + 1(9x) = 20x + 12x + 9x = 41x. 41x = 410 => x = 10. Number of Rs 2 coins = 6x = 60.
7216
If 10% of x = 15% of y = 20% of z, find x:y:z.
Answer:
6:4:3
10x = 15y = 20z. Divide by 5: 2x = 3y = 4z = k. x=k/2, y=k/3, z=k/4. Multiply by LCM(2,3,4)=12 to get 6:4:3.
7217
Two numbers are in ratio 2:3. If their product is 96, find the sum of the numbers.
Answer:
20
Let numbers be 2x and 3x. Product = 6x^2 = 96 => x^2 = 16 => x = 4. Numbers are 8 and 12. Sum = 8 + 12 = 20.
7218
What is the ratio of 40 paise to Rs 2?
Answer:
1:5
Rs 2 = 200 paise. Ratio = 40 : 200. Dividing both by 40 gives 1 : 5.
7219
If a, b, c are in continued proportion, then b^2 is equal to:
Answer:
ac
By definition of continued proportion, a/b = b/c. Cross-multiplying gives b^2 = ac.
7220
The ratio of two numbers is 3:4 and their sum is 420. The greater of the two numbers is:
Answer:
240
Let numbers be 3x, 4x. Sum = 7x = 420 => x = 60. Greater number = 4x = 4 * 60 = 240.