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
151
What annual installment will discharge a debt of Rs. 1092 due in 3 years at 12% simple interest?
Answer:
Rs. 325
Let the annual installment be x. Total amount = x + (x + x×12×1)/100 + (x + x×12×2)/100 = x + 1.12x + 1.24x = 3.36x. So, 3.36x = 1092 => x = 1092 / 3.36 = Rs. 325.
152
A certain sum at simple interest amounts to Rs. 1350 in 5 years and to Rs. 1620 in 8 years. What is the sum?
Answer:
Rs. 900
SI for 3 years (8 - 5) = 1620 - 1350 = Rs. 270. SI for 1 year = 90. SI for 5 years = 450. Principal = 1350 - 450 = Rs. 900.
153
Rs. 5000 is invested for 2 years under compound interest at 10% p.a. The amount generated is:
Answer:
Rs. 6050
Amount A = P(1 + R/100)^T = 5000(1 + 10/100)² = 5000(1.10)² = 5000 × 1.21 = Rs. 6050.
154
A sum of money at simple interest amounts to Rs. 2240 in 2 years and to Rs. 2600 in 5 years. What is the principal amount?
Answer:
Rs. 2000
SI for 3 years (5 - 2) = 2600 - 2240 = Rs. 360. SI for 1 year = Rs. 120. SI for 2 years = 240. Principal = Amount for 2 years - SI for 2 years = 2240 - 240 = Rs. 2000.
155
The simple interest on a certain sum of money for 4 years at 4% per annum exceeds the compound interest on the same sum for 3 years at 5% per annum by Rs. 57. Find the sum.
Answer:
Rs. 24000
SI for 4 years at 4% = 16% of P. Effective CI rate for 3 years at 5% = 15.7625% of P. Difference = 16% - 15.7625% = 0.2375% of P. Given 0.2375% of P = 57. P = (57 × 100) / 0.2375 = 5700 / 0.2375 = Rs. 24000.
156
A sum of money amounts to Rs. 1016 in 2.5 years and to Rs. 1112 in 4 years at simple interest. The principal is:
Answer:
Rs. 856
SI for 1.5 years (4 - 2.5) = 1112 - 1016 = Rs. 96. SI for 1 year = 96 / 1.5 = Rs. 64. SI for 2.5 years = 64 × 2.5 = Rs. 160. Principal = 1016 - 160 = Rs. 856.
157
Find the simple interest on Rs. 4000 at 12% per annum for 18 months.
Answer:
Rs. 720
Time T = 18 months = 1.5 years. SI = (P × R × T)/100 = (4000 × 12 × 1.5)/100 = 40 × 18 = Rs. 720.
158
The population of a town is 10,000. It increases by 10% during the first year and 20% during the second year. What is the population after 2 years?
Answer:
13200
Population after 1st year = 10000 × 1.10 = 11000. Population after 2nd year = 11000 × 1.20 = 13200.
159
What will be the amount of Rs. 50000 after 2 years, compounded annually; the rate of interest being 8% p.a. during the first year and 9% p.a. during the second year?
Answer:
Rs. 58860
Amount A = P(1 + R1/100)(1 + R2/100) = 50000(1 + 8/100)(1 + 9/100) = 50000(1.08)(1.09) = 50000 × 1.1772 = Rs. 58860.
160
Compound interest on a sum of Rs. 10000 for 2 years at 4% per annum is:
Answer:
Rs. 816
Effective CI rate for 2 years at 4% = 4 + 4 + (4×4)/100 = 8.16%. CI = 8.16% of 10000 = Rs. 816.