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
261
Find the single discount equivalent to a series discount of 20%, 10% and 5%.
Answer:
31.6%
Let original price = 100. After 20% discount, price = 80. After 10% discount on 80, price = 80 - 8 = 72. After 5% discount on 72, price = 72 - (0.05 * 72) = 72 - 3.6 = 68.4. Total discount = 100 - 68.4 = 31.6%.
262
An article is sold at a certain price. By selling it at 2/3 of that price one loses 10%. Find the gain percent at original price.
Answer:
35%
Let the original SP be 3x. The new SP is 2/3 * 3x = 2x. At 2x, the loss is 10%, meaning 2x = 90% of CP. So CP = 2x / 0.9 = 20x / 9. Original profit = Original SP - CP = 3x - (20x / 9) = 7x / 9. Gain % = (Profit / CP) * 100 = ((7x / 9) / (20x / 9)) * 100 = (7 / 20) * 100 = 35%.
263
A trader marks his goods at 20% above the cost price. If he allows a discount of 5% on marked price, what profit percent does he make?
Answer:
14%
Let CP = 100. MP = 120. Discount is 5% on MP, which is 0.05 * 120 = 6. SP = 120 - 6 = 114. Profit = SP - CP = 114 - 100 = 14. Therefore, profit percentage = 14%.
264
The cost price of an article is 64% of the marked price. Calculate the gain percent after allowing a discount of 12%.
Answer:
37.5%
Let Marked Price (MP) = 100. Then Cost Price (CP) = 64. A discount of 12% is given on MP, so Selling Price (SP) = 100 - 12 = 88. Gain = SP - CP = 88 - 64 = 24. Gain % = (24 / 64) * 100 = (3 / 8) * 100 = 37.5%.
265
By selling an article at 2/3 of the marked price, there is a loss of 10%. The profit percent when the article is sold at the marked price is:
Answer:
35%
Let the Marked Price (MP) be 300. Selling Price (SP) = 2/3 * 300 = 200. This SP results in a 10% loss, so 90% of CP = 200 => CP = 2000 / 9. If sold at MP, Profit = MP - CP = 300 - (2000 / 9) = 700 / 9. Profit % = (Profit / CP) * 100 = ((700 / 9) / (2000 / 9)) * 100 = (7 / 20) * 100 = 35%.
266
A shopkeeper cheats to the extent of 10% while buying and 10% while selling by using false weights. His total gain is:
Answer:
21%
Using the successive percentage formula: Net Gain % = a + b + (ab / 100). Here, a = 10 and b = 10. Net Gain = 10 + 10 + (10 * 10) / 100 = 20 + 1 = 21%. (Note: Modern SSC standards strictly use this formula for 'cheats by x% in buying and selling'.)
267
A sells an article to B making a profit of 1/5 of his outlay. B sells it to C, gaining 20%. If C sells it for Rs. 600 and incurs a loss of 1/6 of his outlay, the cost price for A is:
Answer:
Rs. 500
C incurs a loss of 1/6, meaning SP for C = 5/6 of C's CP. So, 5/6 * (CP of C) = 600 => CP of C = 720. B gains 20% (1/5), so SP for B (which is CP of C) = 6/5 of B's CP. 6/5 * (CP of B) = 720 => CP of B = 600. A gains 1/5, so SP for A = 6/5 of A's CP. 6/5 * (CP of A) = 600 => CP of A = 500.
268
If a man reduces the selling price of a fan from Rs. 400 to Rs. 380, his loss increases by 2%. The cost price of the fan is:
Answer:
Rs. 1000
The reduction in selling price is Rs. 400 - Rs. 380 = Rs. 20. This reduction causes an increase in loss by 2% of the Cost Price. Therefore, 2% of CP = Rs. 20. CP = (20 / 2) * 100 = Rs. 1000.
269
By selling 100 notebooks, a shopkeeper gains the selling price of 20 notebooks. Find his gain percent.
Answer:
25%
Let the SP of 1 notebook be Re. 1. SP of 100 notebooks = Rs. 100. Gain = SP of 20 notebooks = Rs. 20. CP of 100 notebooks = SP - Gain = 100 - 20 = Rs. 80. Gain % = (Gain / CP) * 100 = (20 / 80) * 100 = 25%.
270
An article passing through two hands is sold at a profit of 38% at the original cost price. If the first dealer makes a profit of 20%, then the profit percent made by the second dealer is:
Answer:
15%
Let the original CP be 100. Final SP is 138. First dealer sells it at 20% profit, so his SP (which is the second dealer's CP) = 120. Second dealer sells it at 138. Second dealer's profit = 138 - 120 = 18. Profit % = (18 / 120) * 100 = 15%.