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
191
An article costs Rs. 500. The marked price is set such that after a 10% discount, there is a profit of 20%. Find the marked price.
Answer:
Rs. 666.67
CP = 500. Profit = 20%, so SP = 500 * 1.20 = Rs. 600. A 10% discount on MP gives SP, so 90% of MP = 600. MP = 600 / 0.90 = 6000 / 9 = Rs. 666.67.
192
If a reduction of 10% in the price of sugar enables a housewife to buy 5 kg more for Rs. 300, find the original price per kg of sugar.
Answer:
Rs. 6.66
10% of 300 = Rs. 30. This Rs. 30 buys 5 kg extra. So, the reduced price = 30 / 5 = Rs. 6 per kg. Since the reduced price is 90% of the original price, Original Price = 6 / 0.90 = 60 / 9 = Rs. 6.66 per kg.
193
A fruit seller buys 100 kg of apples at Rs. 50 per kg. 10 kg of apples were rotten and thrown away. At what rate per kg should he sell the remaining apples to get a 20% overall profit?
Answer:
Rs. 66.67
Total CP = 100 * 50 = Rs. 5000. Desired total SP for a 20% profit = 5000 * 1.20 = Rs. 6000. Remaining apples = 100 - 10 = 90 kg. Required SP per kg = 6000 / 90 = 600 / 9 = Rs. 66.67.
194
A man buys apples at 10 for Rs. 25 and sells them at 9 for Rs. 25. Find his profit percentage.
Answer:
11.11%
CP of 1 apple = 25 / 10 = Rs. 2.50. SP of 1 apple = 25 / 9 = Rs. 2.77... Profit = 25/9 - 25/10 = 250/90 - 225/90 = 25/90. Profit % = ((25/90) / (25/10)) * 100 = (10 / 90) * 100 = 11.11%.
195
A trader mixes 20 kg of wheat at Rs. 15 per kg with 30 kg of wheat at Rs. 13 per kg. At what price per kg should he sell the mixture to gain 33.33%?
Answer:
Rs. 18.40
Total Cost Price = (20 * 15) + (30 * 13) = 300 + 390 = 690. Total weight = 50 kg. CP per kg = 690 / 50 = Rs. 13.80. Gain desired is 33.33%, which is 1/3. SP = CP * (1 + 1/3) = CP * 4/3 = 13.80 * 4/3 = 4.60 * 4 = Rs. 18.40.
196
By selling an article for Rs. 21, a man lost a percentage equal to the cost price of the article. What was the cost price?
Answer:
Rs. 30 or Rs. 70
Let the CP be x. Loss % = x%. Loss = (x/100) * x = x^2 / 100. We know SP = CP - Loss => 21 = x - (x^2 / 100). Multiply by 100: 2100 = 100x - x^2. x^2 - 100x + 2100 = 0. Solving this quadratic equation: (x - 30)(x - 70) = 0. So, x = 30 or 70. Both values are valid.
197
If a manufacturer gains 10%, wholesale dealer 15% and retailer 25%, find the cost of production of a table if the retail price is Rs. 1265.
Answer:
Rs. 800
Let the cost of production be x. x * 1.10 * 1.15 * 1.25 = 1265. x * 1.58125 = 1265. x = 1265 / 1.58125 = Rs. 800.
198
When a discount of 20% is given on a sweater, the profit is 28%. If the discount is 14%, what will be the profit?
Answer:
37.6%
Let CP = 100. For a 28% profit, SP = 128. This SP is after a 20% discount on MP, so 80% of MP = 128 => MP = 128 / 0.8 = 160. If the discount is 14%, new SP = 86% of MP = 0.86 * 160 = 137.6. Profit = 137.6 - 100 = 37.6. Profit % = 37.6%.
199
An article is sold at 15% profit. If it is sold for Rs. 27 more, the profit will be 20%. The cost price of the article is:
Answer:
Rs. 540
The difference in profit percentage is 20% - 15% = 5%. This 5% of CP equals Rs. 27. So, 0.05 * CP = 27 => CP = 27 / 0.05 = Rs. 540.
200
A man bought two goats for Rs. 1008. He sold one at a loss of 20% and other at a profit of 44%. If each goat was sold for the same price, the cost price of the goat which was sold at a loss was:
Answer:
Rs. 648
Let CP of the first goat (sold at loss) be x. Then CP of the second is 1008 - x. The selling prices are equal: 80% of x = 144% of (1008 - x). So, 0.8x = 1.44(1008 - x) => 80x = 144(1008) - 144x => 224x = 144 * 1008. x = (144 * 1008) / 224 = 648. CP of the first goat = Rs. 648.