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
111
A trader sold a TV at a 20% profit. If he had bought it at 20% less and sold it for Rs. 900 less, he would have gained 25%. The cost price of the TV is:
Answer:
Rs. 4500
Let CP = x. Original SP = 1.20x. New CP = 0.80x. New SP = 1.20x - 900. New gain = 25% on new CP. So, New SP = 1.25 * 0.80x = 1.00x. Equating the two: 1.20x - 900 = 1.00x => 0.20x = 900 => x = 900 / 0.20 = 4500. CP = Rs. 4500.
112
A man purchased two articles for Rs. 3000 each. He sold one at a 15% profit and the other at a 15% loss. His total profit or loss is:
Answer:
No profit no loss
When two articles have the same Cost Price, and one is sold at +x% and the other at -x%, the net result is always exactly 0. Thus, there is no profit and no loss.
113
If the profit earned on selling an article for Rs. 800 is equal to the loss incurred on selling it for Rs. 400, the cost price of the article is:
Answer:
Rs. 600
Since Profit = Loss, SP1 - CP = CP - SP2. 800 - CP = CP - 400 => 2CP = 1200 => CP = Rs. 600.
114
A shopkeeper allows a 10% discount on his goods and still earns a 20% profit. If an item costs him Rs. 600, what is its marked price?
Answer:
Rs. 800
CP = 600. For 20% profit, SP = 600 * 1.20 = 720. Since SP is after a 10% discount, 90% of MP = 720. MP = 720 / 0.90 = Rs. 800.
115
A trader mixes two varieties of sugar at Rs. 20/kg and Rs. 30/kg. If he sells the mixture at Rs. 27/kg and makes a 20% profit, what is the ratio in which they were mixed?
Answer:
3:1
SP = 27. Profit = 20%. CP of mixture = 27 / 1.20 = 22.5. Using alligation: Quantity of cheaper / Quantity of dearer = (30 - 22.5) / (22.5 - 20) = 7.5 / 2.5 = 3:1.
116
A shopkeeper bought 20 kg of wheat at Rs. 15 per kg and 30 kg at Rs. 13 per kg. He sold the mixture at Rs. 16 per kg. His total profit is:
Answer:
Rs. 110
Total CP = (20 * 15) + (30 * 13) = 300 + 390 = 690. Total weight = 50 kg. Total SP = 50 * 16 = 800. Total Profit = 800 - 690 = Rs. 110.
117
A boy buys 3 apples for Rs. 5 and sells them at 4 for Rs. 7. His profit or loss percent is:
Answer:
5% profit
CP of 1 apple = 5/3. SP of 1 apple = 7/4. Let's assume total 12 apples. CP = 12 * (5/3) = 20. SP = 12 * (7/4) = 21. Profit = 21 - 20 = 1. Profit % = (1 / 20) * 100 = 5% profit.
118
Find the single discount equivalent to three successive discounts of 10%, 20%, and 25%.
Answer:
46%
Let MP = 100. After 10%, price = 90. After 20% on 90, price = 90 - 18 = 72. After 25% on 72, price = 72 - 18 = 54. The final price is 54, which means the total discount is 100 - 54 = 46%.
119
A merchant marks his goods at Rs. 450. After allowing a 20% discount, he earns a profit of 20%. The cost price of the goods is:
Answer:
Rs. 300
MP = 450. Discount = 20% of 450 = 90. SP = 450 - 90 = 360. Profit is 20%, meaning SP = 120% of CP. 1.20 * CP = 360 => CP = 360 / 1.2 = Rs. 300.
120
A trader marks up his goods by 25% and offers a 10% discount. Further, he uses a 900g weight instead of 1 kg. His overall profit percentage is:
Answer:
25%
Let true CP for 1000g be 100. He uses 900g, so his actual cost is 90. He marks up 1000g to 125, then gives a 10% discount on 125, so SP = 125 - 12.5 = 112.5. Profit = 112.5 - 90 = 22.5. Profit % = (22.5 / 90) * 100 = 25%.