About this quiz
50 questions covering every section of the note on interest terms, simple interest, finding P, T or R, doubling time, months and days, yearly and half-yearly compound interest, the CI minus SI shortcut and the step-by-step method.
This Lok Sewa practice set has 50 multiple-choice questions (Subject: Maths and IQ · For: Kharidar, Nayab Subba, Section Officer · Level: Medium). Take the quiz above first; after that, use the study list below to revise every question with its correct answer and a short explanation.
Study list: all 50 questions with answers and explanations
Hari borrows Rs 6,000 and pays back Rs 7,080 in total. How much interest did he pay?
- A) Rs 1,180
- B) Rs 1,080 ✔
- C) Rs 980
- D) Rs 7,080
Why: Interest = amount − principal = 7,080 − 6,000 = Rs 1,080.
What is the simple interest on Rs 7,500 at 8% per annum for 3 years?
- A) Rs 600
- B) Rs 1,600
- C) Rs 1,800 ✔
- D) Rs 2,400
Why: SI = 7,500 × 3 × 8/100 = Rs 1,800.
In the step-by-step method for compound interest at 10% per annum compounded yearly, by which factor is the principal multiplied once for each year?
- A) 1.1 ✔
- B) 0.1
- C) 1.01
- D) 10
Why: The rate is turned into a factor: 1 + 10/100 = 1.1, and the principal is multiplied by 1.1 once for each year.
A sum earns Rs 2,700 as simple interest in 3 years at 12% per annum. What is the sum?
- A) Rs 9,720
- B) Rs 6,750
- C) Rs 8,100
- D) Rs 7,500 ✔
Why: P = 2,700 × 100/(3 × 12) = 270,000/36 = Rs 7,500.
Rs 12,000 earns Rs 3,600 simple interest in 5 years. What is the rate per annum?
- A) 5%
- B) 6% ✔
- C) 7.5%
- D) 30%
Why: R = 3,600 × 100/(12,000 × 5) = 6%.
In how many years will Rs 8,000 earn Rs 1,800 simple interest at 7.5% per annum?
- A) 3 years ✔
- B) 4 years
- C) 2.5 years
- D) 2.25 years
Why: T = 1,800 × 100/(8,000 × 7.5) = 180,000/60,000 = 3 years.
A sum amounts to Rs 11,200 in 4 years at 10% per annum simple interest. What is the sum?
- A) Rs 10,080
- B) Rs 7,200
- C) Rs 8,000 ✔
- D) Rs 8,400
Why: P = A × 100/(100 + R × T) = 11,200 × 100/140 = Rs 8,000.
At simple interest a sum amounts to Rs 6,600 in 2 years and Rs 7,200 in 4 years. What is the principal?
- A) Rs 6,300
- B) Rs 5,400
- C) Rs 4,800
- D) Rs 6,000 ✔
Why: Interest for 2 extra years = 600, so 300 per year. P = 6,600 − 2 × 300 = Rs 6,000.
At 12.5% per annum simple interest, in how many years will a sum double itself?
- A) 12.5 years
- B) 10 years
- C) 8 years ✔
- D) 16 years
Why: T = (2 − 1) × 100/12.5 = 8 years.
At 8% per annum simple interest, in how many years will a sum become three times itself?
- A) 12.5 years
- B) 25 years ✔
- C) 37.5 years
- D) 24 years
Why: Interest needed = 2 × P, so T = 2 × 100/8 = 25 years.
A sum doubles itself in 10 years at simple interest. In how many years will it become 4 times itself at the same rate?
- A) 30 years ✔
- B) 20 years
- C) 40 years
- D) 25 years
Why: Rate = 100/10 = 10%. For 4 times, interest = 3 × P, so T = 3 × 100/10 = 30 years.
What is the simple interest on Rs 15,000 at 8% per annum for 7 months?
- A) Rs 8,400
- B) Rs 840
- C) Rs 750
- D) Rs 700 ✔
Why: SI = 15,000 × 7/12 × 8/100 = 1,250 × 7 × 8/100 = Rs 700.
What is the simple interest on Rs 14,600 at 10% per annum for 146 days?
- A) Rs 1,460
- B) Rs 584 ✔
- C) Rs 365
- D) Rs 5,840
Why: T = 146/365 = 0.4 year; SI = 14,600 × 0.4 × 10/100 = Rs 584.
Find the simple interest on Rs 6,400 at 12% per annum for 2 years 3 months.
- A) Rs 1,536
- B) Rs 1,600
- C) Rs 1,792
- D) Rs 1,728 ✔
Why: T = 2 + 3/12 = 2.25 years; SI = 6,400 × 2.25 × 12/100 = Rs 1,728.
What amount will Rs 5,000 become in 2 years at 10% per annum compounded yearly?
- A) Rs 6,050 ✔
- B) Rs 6,000
- C) Rs 5,500
- D) Rs 6,100
Why: A = 5,000 × 1.1 × 1.1 = 5,000 × 1.21 = Rs 6,050.
Find the compound interest on Rs 12,000 at 5% per annum for 2 years, compounded yearly.
- A) Rs 1,200
- B) Rs 13,230
- C) Rs 1,230 ✔
- D) Rs 1,260
Why: A = 12,000 × 1.05 × 1.05 = 13,230; CI = 13,230 − 12,000 = Rs 1,230.
Find the compound interest on Rs 10,000 at 10% per annum for 3 years, compounded yearly.
- A) Rs 3,000
- B) Rs 3,310 ✔
- C) Rs 3,210
- D) Rs 13,310
Why: A = 10,000 × 1.1³ = 10,000 × 1.331 = 13,310; CI = Rs 3,310.
What will Rs 16,000 amount to in 3 years at 5% per annum compounded yearly?
- A) Rs 18,522 ✔
- B) Rs 18,400
- C) Rs 18,700
- D) Rs 2,522
Why: A = 16,000 × 1.05³ = 16,000 × 1.157625 = Rs 18,522.
On Rs 10,000 at 10% per annum compounded yearly, what is the interest for the second year only?
- A) Rs 1,000
- B) Rs 2,100
- C) Rs 1,210
- D) Rs 1,100 ✔
Why: After year 1 the sum is 11,000; interest for year 2 = 11,000 × 10/100 = Rs 1,100.
Find the compound interest on Rs 20,000 for 1 year at 8% per annum, compounded half-yearly.
- A) Rs 1,600
- B) Rs 1,664
- C) Rs 1,632 ✔
- D) Rs 21,632
Why: Rate per half-year = 4%, periods = 2. A = 20,000 × 1.04 × 1.04 = 21,632; CI = Rs 1,632.
Interest at 12% per annum is compounded half-yearly for 2 years. What are the rate per period and the number of periods?
- A) 6% and 4 periods ✔
- B) 12% and 2 periods
- C) 6% and 2 periods
- D) 24% and 4 periods
Why: Half-yearly: rate = 12/2 = 6% per half-year and periods = 2 × 2 = 4.
What is the difference between compound interest and simple interest on Rs 15,000 for 2 years at 8% per annum?
- A) Rs 120
- B) Rs 96 ✔
- C) Rs 960
- D) Rs 64
Why: Difference = P × (R/100)² = 15,000 × 0.08 × 0.08 = 15,000 × 0.0064 = Rs 96.
The difference between CI and SI on a sum for 2 years at 6% per annum is Rs 72. What is the sum?
- A) Rs 12,000
- B) Rs 1,200
- C) Rs 24,000
- D) Rs 20,000 ✔
Why: P = 72 ÷ (6/100)² = 72 ÷ 0.0036 = Rs 20,000.
Rs 6,250 amounts to Rs 7,290 in 2 years at compound interest, compounded yearly. What is the rate per annum?
- A) 10%
- B) 9%
- C) 8% ✔
- D) 8.5%
Why: (1 + R/100)² = 7,290/6,250 = 1.1664 = 1.08 × 1.08, so R = 8%.
What is the difference between CI (compounded yearly) and SI on Rs 8,000 at 10% per annum for 1 year?
- A) Rs 0 ✔
- B) Rs 80
- C) Rs 8
- D) Rs 800
Why: For the first year CI and SI are equal: both are 8,000 × 10/100 = 800, so the difference is Rs 0.
Simple interest is calculated as:
- A) P × T × R ÷ 100 ✔
- B) P × R ÷ T
- C) P + T + R
- D) P × (1 + R)^T
Why: SI formula.
SI on Rs 5,000 at 10% per year for 3 years:
- A) Rs 1,500 ✔
- B) Rs 1,000
- C) Rs 1,650
- D) Rs 500
Why: 5,000 × 3 × 10 ÷ 100.
SI on Rs 8,000 at 5% for 2 years:
- A) Rs 800 ✔
- B) Rs 400
- C) Rs 820
- D) Rs 1,600
Why: 8,000 × 0.1.
Amount of Rs 10,000 at 8% SI for 5 years:
- A) Rs 14,000 ✔
- B) Rs 4,000
- C) Rs 14,693
- D) Rs 18,000
Why: SI 4,000.
Rs 4,000 earns Rs 1,200 SI in 5 years. Rate:
- A) 6% ✔
- B) 5%
- C) 3%
- D) 8%
Why: 1,200 ÷ (4,000 × 5) × 100.
In how many years will Rs 2,500 earn Rs 500 at 4% SI?
- A) 5 ✔
- B) 4
- C) 6
- D) 2
Why: 500 ÷ 100.
SI is Rs 900 at 6% for 3 years. Principal:
- A) Rs 5,000 ✔
- B) Rs 4,500
- C) Rs 6,000
- D) Rs 3,000
Why: 900 × 100 ÷ 18.
A sum triples in 20 years at SI. Rate:
- A) 10% ✔
- B) 15%
- C) 5%
- D) 20%
Why: Interest = 2P in 20 years.
At 12.5% SI, a sum doubles in:
- A) 8 years ✔
- B) 10 years
- C) 12 years
- D) 6 years
Why: 100 ÷ 12.5.
CI on Rs 5,000 at 10% for 2 years (annually):
- A) Rs 1,050 ✔
- B) Rs 1,000
- C) Rs 1,100
- D) Rs 1,025
Why: 5,000 × 1.21 − 5,000.
Amount of Rs 8,000 at 5% CI for 2 years:
- A) Rs 8,820 ✔
- B) Rs 8,800
- C) Rs 8,400
- D) Rs 9,000
Why: 8,000 × 1.1025.
CI on Rs 1,000 at 20% for 2 years:
- A) Rs 440 ✔
- B) Rs 400
- C) Rs 420
- D) Rs 480
Why: 1,000 × 1.44 − 1,000.
Difference between CI and SI on Rs 5,000 at 10% for 2 years:
- A) Rs 50 ✔
- B) Rs 100
- C) Rs 25
- D) Rs 500
Why: P(R/100)².
Interest at 10% p.a. compounded half-yearly means a rate per half-year of:
- A) 5% ✔
- B) 10%
- C) 20%
- D) 2.5%
Why: Half the annual rate.
Interest at 12% p.a. compounded quarterly means a rate per quarter of:
- A) 3% ✔
- B) 4%
- C) 12%
- D) 6%
Why: 12 ÷ 4.
For one year with annual compounding, CI and SI are:
- A) Equal ✔
- B) CI greater
- C) SI greater
- D) Zero
Why: Same for 1 period.
Amount of Rs 2,000 at 10% CI for 3 years:
- A) Rs 2,662 ✔
- B) Rs 2,600
- C) Rs 2,620
- D) Rs 2,700
Why: 2,000 × 1.331.
Population growth is calculated with a formula similar to:
- A) Compound interest ✔
- B) Simple interest
- C) Discount
- D) Average
Why: Growth on growth.
A machine worth Rs 50,000 depreciates 10% a year. Value after 2 years:
- A) Rs 40,500 ✔
- B) Rs 40,000
- C) Rs 45,000
- D) Rs 41,000
Why: 50,000 × 0.81.
SI on Rs 12,000 at 7.5% for 2 years:
- A) Rs 1,800 ✔
- B) Rs 900
- C) Rs 1,500
- D) Rs 2,000
Why: 12,000 × 0.15.
SI on Rs 6,000 for 73 days at 10% per year:
- A) Rs 120 ✔
- B) Rs 600
- C) Rs 73
- D) Rs 160
Why: 6,000 × 0.1 × 73/365.
Interest rates of banks in Nepal are regulated by:
- A) Nepal Rastra Bank ✔
- B) Ministry of Finance
- C) NEPSE
- D) SEBON
Why: Central bank.
At what SI rate does Rs 1,500 become Rs 1,800 in 4 years?
- A) 5% ✔
- B) 4%
- C) 6%
- D) 7.5%
Why: 300 ÷ 6,000 × 100.
A sum doubles in 5 years at CI. It becomes 4 times in:
- A) 10 years ✔
- B) 20 years
- C) 15 years
- D) 8 years
Why: Doubles again in 5 more.
In CI, interest is charged on:
- A) Principal plus earlier interest ✔
- B) Principal only
- C) Interest only
- D) Nothing
Why: Interest on interest.