# Simple and Compound Interest Questions for RRB NTPC Set-4

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### Simple and Compound Interest Questions for RRB NTPC Set-4

Download RRB NTPC Simple and Compound Interest Questions Set-4 PDF. Top 10 RRB NTPC questions based on asked questions in previous exam papers very important for the Railway NTPC exam.

Question 1: The simple interest at the rate of 8% on the amount Rs. 20,000 for 3 months is

a) 400

b) 600

c) 500

d) 200

Question 2: A certain amount which was loaned on simple interest doubled in 10 years Then the amount received is loaned on compound interest for another 2 years on the same rate What is the total rise in the amount after 12 years with the initial principal amount ?

a) 42%

b) 142%

c) 242%

d) 150%

Question 3: One-fourth of an amount was loaned at simple interest with 2% rate of interest and the remaining part was lent on simple interest at 3% rate of interest What is the average rate of interest for the whole amount ?

a) $2\frac{1}{4}\%$

b) $2\frac{3}{4}\%$

c) $1\frac{1}{4}\%$

d) $4\%$

Question 4: The simple interest on a certain sum at the rate of 4% per annum in 4 years is Rs. 80 more than the simple interest on the same sum at 5% per annum after 3 years. The sum is

a) Rs. 7000

b) Rs. 7,500

c) Rs. 8000

d) Rs. 8,500

Question 5: Find the simple interest on ₹ 4800 at the rate of $8 \frac{1}{2}$% per annum for a period of 2 years 3 months.

a) ₹ 796

b) ₹ 816

c) ₹ 918

d) ₹ 990

Question 6: What is the difference between Compound Interest and Simple Interest on Rs.1000 at 10% after 4 years?

a) Rs.64.10

b) Rs.74

c) Rs.16.40

d) Rs.52

Question 7: The Compound Interest on a certain sum for 2 years at 10% is Rs.2100. What will be the Simple Interest for the same period, on the same sum and at the same rate?

a) Rs.2000

b) Rs.1600

c) Rs.1800

d) Rs.1980

Question 8: Find the difference between the Simple Interest and Compound Interest on Rs.10000 for 3 years at the rate of 3% per annum.

a) Rs.27.27

b) Rs.17.82

c) Rs.21.54

d) Rs.16.25

Question 9: Compound Interest and Simple Interest on a certain sum of money for 2 years is Rs.282.15 and Rs.270 respectively. The rate of interest is:

a) 6$\frac{2}{3}$%

b) 11%

c) 9%

d) 8$\frac{1}{3}$%

Question 10: On a sum of money, the Simple Interest for 2 years is Rs.660 while the Compound Interest for two years is Rs.696.30, the rate of interest being the same. Find the rate of interest.

a) 10%

b) 12.75%

c) 11%

d) 13%

S.I=P x r x t/100 , t in years

=(20,000 x 8 x 3)/( 100 x 12)=400

The amount doubled in 10 years. So, the interest = principle.

So, rt/100 = 1

r = 10% pa

Now compound interest = ?

2P $(1 + .1) ^ {2}$  = 2P x 1.21 = 2.42P

Total rise is P to 2.42P = rise of 142%

Let the amount be 100 Rs.

One fourth of it is at 2 % pa

So, 25 x 2 x 1 /100 = .5

The rest is on 3% pa interest.

So, 75 x 3 x 1 /100 = 2.25

So total interest = 2.75

Interest rate = ?

Interest rate = i x 100/ pt

= 2.75 x100/100 = 2.75%

Let the principal be P

SI = P xT x R/100

difference = P x 4 x 4 /100 – P x 5 x 3/100

= 16P/100 – 15P/100 = 80

P = 8000 Rs.

Given that P = 4800, T = 2.25, R = 8.5

We know that Simple Interest $I = \frac{PTR}{100}$

Therefore,$I = \frac{4800 \times 2.25 \times 8.5}{100}$

=> $I = \frac{91800}{100} = Rs 918/-$

Simple interest SI= P× N×R ÷ 100

P=principle amount

N= Time period

R= rate of interest

SI=1000×10×4÷100

SI=400

For compound interest (CI)

Amount=P×(1+R÷100)^N

Amount=1000×(1+10÷100)^4

Amount=1464.1

Amount=P+CI

CI=Amount-P

CI=464.1

CI-SI=64.1

amount= principle+interest

compound interest,

$amt = p \times (1+ \frac{r}{100})^n$

amt=p+interest

interest=2100

r=10%

n=2

$p+2100 = p \times (1+ \frac{10}{100})^2$

solving we get p=10000

simple interest

$si= \frac{p \times n \times r}{100}$

p=10000

n=2

r=10%

substituting

$si= \frac{10000 \times 10 \times 2}{100}$

=2000

SI = $\frac{PNR}{100}$

CI = $P(1 + \frac{r}{100})^n$

P = 10000

N = 3 years

R = 3%

$SI = \frac{10000 \times 3 \times 3}{100} = 900$

CI = $10000(1 + \frac{3}{100})^3$

= 927.27

CI – SI = 927.27 – 900 = 27.27

CI for 2 years = Rs 282.15

SI for 2 years = Rs 270

SI for 1 year = $\frac{270}{2} =135$

difference between SI and CI = 282.15 – 270 = 12.15 Rs

rate% = $\frac{12.15}{135} \times 100 = 9$%

for 1st year CI and SI will be same

Difference in C.I and S.I for 2 years

= Rs(696.30-660)

=Rs. 36.30.

S.I for one years = Rs330.

S.I on Rs.330 for 1 year =Rs. 36.30

$R=\frac{S.I\times100}{{P}\times{T}}$

Rate

$= \frac{100\times36.30}{330\times1}$

= 11%

We hope this Simple and Compound Interest Questions set-4 pdf for RRB NTPC exam will be highly useful for your Preparation.