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
271
A man bought a horse and a carriage for Rs. 3000. He sold the horse at a gain of 20% and the carriage at a loss of 10%, thereby gaining 2% on the whole. Find the cost of the horse.
Answer:
Rs. 1200
Using the method of alligation: Gain on horse = +20%, Loss on carriage = -10%, Overall gain = +2%. The ratio of CP of horse to carriage is (2 - (-10)) : (20 - 2) = 12 : 18 = 2 : 3. The total CP is 3000. CP of horse = (2 / 5) * 3000 = Rs. 1200.
272
A dishonest milkman professes to sell his milk at cost price but he mixes it with water and thereby gains 25%. The percentage of water in the mixture is:
Answer:
20%
To gain 25% by selling at the cost price of pure milk, the ratio of water to milk must be 25:100, or 1:4. This means in 5 parts of the mixture, there is 1 part water and 4 parts milk. The percentage of water in the mixture = (1 / 5) * 100 = 20%.
273
A trader mixes 26 kg of rice at Rs. 20 per kg with 30 kg of rice of another variety at Rs. 36 per kg and sells the mixture at Rs. 30 per kg. His profit percent is:
Answer:
5%
Total Cost Price = (26 * 20) + (30 * 36) = 520 + 1080 = Rs. 1600. Total weight = 26 + 30 = 56 kg. Total Selling Price = 56 * 30 = Rs. 1680. Profit = 1680 - 1600 = Rs. 80. Profit % = (80 / 1600) * 100 = 5%.
274
The marked price of a shirt is Rs. 1500. After two successive discounts of 20% and 10%, what will be the selling price?
Answer:
Rs. 1080
Marked Price = Rs. 1500. First discount is 20%, so price becomes 80% of 1500 = 0.80 * 1500 = 1200. Second discount is 10% on Rs. 1200, so price becomes 90% of 1200 = 0.90 * 1200 = Rs. 1080.
275
A sells a bicycle to B at a profit of 20%. B sells it to C at a profit of 25%. If C pays Rs. 1500 for it, what did A pay for it?
Answer:
Rs. 1000
Let the CP for A be x. A sells it for 1.20x. B sells it to C for a 25% profit on his cost, so SP for B = 1.25 * (1.20x) = 1.50x. C pays 1500, so 1.50x = 1500. x = 1500 / 1.50 = 1000. A paid Rs. 1000 for it.
276
If an article is sold at a 10% discount, a profit of 20% is made. If the discount is 20%, what will be the profit percentage?
Answer:
6.66%
Let CP = 100. Profit = 20%, so SP = 120. This SP is after a 10% discount on MP. So, 90% of MP = 120, giving MP = 120 / 0.9 = 400 / 3. Now, if the discount is 20%, the new SP = 80% of MP = 0.8 * (400 / 3) = 320 / 3 = 106.66. Profit = 106.66 - 100 = 6.66. Profit % = 6.66%.
277
A merchant marks his goods up by 40% and then offers a 20% discount. Find his profit percentage.
Answer:
12%
Let CP = 100. The Marked Price (MP) is 40% higher, so MP = 140. He gives a 20% discount on the MP. Discount = 20% of 140 = 28. Selling Price (SP) = 140 - 28 = 112. Since SP is 112 and CP is 100, Profit = 112 - 100 = Rs. 12. Profit percentage = 12%.
278
A shopkeeper sells an article at a loss of 12.5%. Had he sold it for Rs. 51.80 more, he would have earned a profit of 6%. The cost price of the article is:
Answer:
Rs. 280
Let the Cost Price be x. The difference in SP is the sum of the loss percentage and profit percentage because they are on opposite sides of the cost price. Difference = 12.5% + 6% = 18.5%. Therefore, 18.5% of x = 51.80. x = (51.80 * 100) / 18.5 = 5180 / 18.5 = Rs. 280.
279
Some articles were bought at 6 articles for Rs. 5 and sold at 5 articles for Rs. 6. The gain percent is:
Answer:
44%
To easily compare, let's take a common multiple of the quantities, 30 articles. CP of 30 articles = (5/6) * 30 = Rs. 25. SP of 30 articles = (6/5) * 30 = Rs. 36. Gain = 36 - 25 = Rs. 11. Gain % = (11 / 25) * 100 = 11 * 4 = 44%.
280
A man buys a cycle for Rs. 1400 and sells it at a loss of 15%. What is the selling price of the cycle?
Answer:
Rs. 1190
Cost Price (CP) = Rs. 1400. Loss is 15% of CP = (15 / 100) * 1400 = Rs. 210. Selling Price (SP) = CP - Loss = 1400 - 210 = Rs. 1190. Alternatively, SP = 85% of CP = 0.85 * 1400 = Rs. 1190.