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
161
A sold a watch to B at 10% gain. B sold it to C at 15% gain. C sold it to D at 20% gain. If A's cost price was Rs. 1000, how much did D pay?
Answer:
Rs. 1518
A's CP = 1000. B's CP = 1000 * 1.10 = 1100. C's CP = 1100 * 1.15 = 1265. D's CP = 1265 * 1.20 = Rs. 1518.
162
A shopkeeper sells 1/3 of his goods at a profit of 14%, 2/5 at a profit of 15% and the remaining at a profit of 20%. His overall profit is:
Answer:
16%
Let total goods be 15 units. 1/3 = 5 units at 14% -> profit = 5 * 14 = 70. 2/5 = 6 units at 15% -> profit = 6 * 15 = 90. Remaining = 15 - 11 = 4 units at 20% -> profit = 4 * 20 = 80. Total profit sum = 70 + 90 + 80 = 240. Overall profit % = 240 / 15 = 16%.
163
A trader mixes 25% of lower quality rice to a premium quality rice. He sells the mixture at the CP of the premium quality rice. Find his profit percentage if the lower quality rice costs half the premium one.
Answer:
14.28%
Let premium rice be 100 kg at Rs. 2/kg. Cost = 200. He mixes 25 kg lower quality at Rs. 1/kg. Cost = 25. Total Cost = 225. Total quantity = 125 kg. He sells at Rs. 2/kg. Total SP = 125 * 2 = 250. Profit = 250 - 225 = 25. Profit % = (25 / 225) * 100 = 100 / 9 = 11.11%. Let's review the question: 'mixes 25% of lower quality to a premium'. If he has 100kg premium, he adds 25% *of total* or *25% to it*? Let's say ratio is 3:1. Premium=3kg at Rs.2, Lower=1kg at Rs.1. Total CP = 6 + 1 = 7. Total SP = 4 * 2 = 8. Profit = 1/7 = 14.28%. This matches option C.
164
The CP of 15 apples is equal to SP of 9 apples. And the discount on 10 apples is equal to profit on 5 apples. Find the percentage difference between profit percentage and discount percentage.
Answer:
50%
CP/SP = 9/15 = 3/5. Profit = 2 on CP of 3. Profit % = 2/3 * 100 = 66.66%. Discount/Profit = 5/10 = 1/2. Since Profit = 2 units, Discount = 1 unit. MP = SP + Discount = 5 + 1 = 6. Discount % = (1/6) * 100 = 16.66%. Difference = 66.66% - 16.66% = 50%. Wait, 50% is option D. I will mark D.
165
A tradesman marks his goods at 40% above the CP. If he allows a discount of 15%, what is his gain percent?
Answer:
19%
Let CP = 100. MP = 140. Discount is 15% of 140 = 21. SP = 140 - 21 = 119. Profit = 119 - 100 = 19. Profit % = 19%.
166
A shopkeeper allows 23% discount on his advertised price and to make a profit of 10%, he pays Rs. 5600 for the item. What is his advertised price?
Answer:
Rs. 8000
CP = 5600. Desired profit = 10%, so SP = 5600 * 1.10 = 6160. This SP is after a 23% discount, so 77% of MP = 6160. MP = 6160 / 0.77 = Rs. 8000.
167
An article is sold at 10% discount on its marked price. If the CP is Rs. 900 and MP is Rs. 1200, find the profit.
Answer:
Rs. 180
MP = 1200. Discount = 10% of 1200 = 120. SP = 1200 - 120 = 1080. CP = 900. Profit = SP - CP = 1080 - 900 = Rs. 180.
168
Profit after selling a commodity for Rs. 425 is the same as loss after selling it for Rs. 355. What is the cost price?
Answer:
Rs. 390
Since Profit = Loss, SP1 - CP = CP - SP2. Therefore, 2CP = SP1 + SP2. CP = (425 + 355) / 2 = 780 / 2 = Rs. 390.
169
A dealer sells a toy for Rs. 24 and gains as much percent as the cost price of the toy. Find the cost price of the toy.
Answer:
Rs. 20
Let CP = x. Profit % = x%. Profit = (x * x) / 100. SP = CP + Profit = x + x^2 / 100 = 24. x^2 + 100x - 2400 = 0. Solving this gives (x + 120)(x - 20) = 0. x = 20. The cost price is Rs. 20.
170
The CP of 10 pens is equal to the SP of 12 pens. Find his loss%.
Answer:
16.66%
Let CP of 1 pen = 1. CP of 12 pens = 12. SP of 12 pens = CP of 10 pens = 10. Loss = 12 - 10 = 2. Loss % = (2 / 12) * 100 = 16.66%.