Simple Interest Question Solve in Simple Ways – Solve the Question in 1 Minute – codewindow.in

/ Aptitude / By Coder_Shark

Simple Interest is one of the most common topics across all competitive and academic exams.

Why do you want Interest?
Let us assume one of your friends comes to you and asks for money of 10000 Rs. He will be giving you your money back after 5 years.
Are you really interested in giving money to him if he is just going to return you the same amount of 10000 Rs only after 5 years?
Obviously not !!!. You would be definitely expecting some amount more than that you have given him. This extra amount which you are expecting from a friend is Interest.
We will be focusing on Simple Interest only for now and once you get comfortable with the simple interest we will look for Compound Interest.
Terms/Terminologies in Simple Interest Calculation:

Terms	Symbol	Meaning
Principal	P	Original amount given to / taken from someone.
Number of Years	N	Number of years for which amount given
Rate of Interest	R	Rate of Interest in %
Simple Interest	I or SI	Simple Interest (Extra amount over original amount)
Amount	A	Original Amount + Simple Interest

Formulae:

Only 2 formulae are sufficient to solve any problem of Simple Interest.
It is just the way to use the formulae looking at given values matters.

Formula 1:

Simple Interest = (P * N * R) / 100

Formula 2:

A = P + SI

Type	Given	To Find
Type 1	Out of P, N, R, and I, any 3 values are given	4th value?
Type 2	Out of P, N, R, I, and A any 3 values are given	4th or 5th value?
Type 3	Interest / Amount given for 2 different timeperiods (eg. 3 years and 5 years)	Rate of interest?
Type 4	Principal split into 2 parts and given on 2different Interest rates	Original spited values of Principal?
Type 5	Amount gets x times in n years	Rate of interest?

Type 1:

Question 1:

Find Simple Interest on 8000 Rs at 5% per annum for 4 years?

Solution:

P = Rs. 8000
R = 5 %
N = 4 Years
Simple Interest = (P * N * R) / 100
Simple Interest = (8000 * 4 * 5) / 100
= 80 * 5 * 4
= 80 * 20
= 1600

Answer is Simple Interest is Rs. 1600.

Question 2:

Find Simple Interest on 7500 Rs at 10% per annum for 2 Years 4 Months?

Solution:

P = Rs. 7500
R = 10 %
N = 2 Years 4 months = 7/3 Years

Simple Interest = (P * N * R) / 100
Simple Interest = (7500 * 7 * 10) / (100 * 3)
= 25 * 70
= 1750

Answer is Simple Interest is Rs. 1750.

Question 3:

A sum fetched a total simple interest of 4016.25 Rs at a rate of 9% in 5 years. What is the sum?

Solution:

SI = 4016.25 Rs
R = 9 %
N = 5 Years
P = ?
Simple Interest = (P * N * R) / 100
4016.25 = (P * 5 * 9) / 100
P = 4016.25 * 100 / (5 * 9)
= 4016.25 * 20 / 9
= 446.25 * 20
= 8925.00
= 8925
Answer is Sum is Rs. 8925.

Question 4:

Anil has given amount of 10000 Rs to Sunil at the rate of 10% Simple Interest. After how much duration Sunil has to return money so that Anil will get Interest of 5000Rs?

Solution:

P = Rs. 10000
SI = Rs. 5000
R = 10%
N = ?
5000 = 10000 * N * 10 / 100
N = (5000 * 100) / (10000 * 10)
N = 5
Answer is 5 Years.

Full Set Accenture Question Paper

Type 2:

Question 1:

A sum of 12,500 Rs amounts to 15,500 Rs in 4 years at the rate of simple interest. What is the rate of Interest?

Solution:

P = 12500 Rs
A = 15500 Rs
N = 4 years
R = ?
As you can see here, we have to find rate of interest.
In order to find rate of Interest we need to first find the Simple interest.
A = P + SI
15500 = 12500 + SI
SI = 3000
As per Simple Interest formula,
Simple Interest = (P * N * R) / 100
3000 = 12500 * 4 * R / 100
R = 3000 * 100 / (12500 * 4)
= 3000 * 4 / (500 * 4)
= 6
Answer is Rate of Interest is 6%.

Question 2:

Reema took loan of 1200 Rs with Simple Interest for as many as years as the rate of Interest. If she paid 432 Rs as Interest at the end of loan period, what was rate of Interest?

Solution:

P = 1200 Rs
SI = 432 Rs
N = R = Let us assume it as x
R = ?
Simple Interest = (P * N * R) / 100
432 = 1200 * x * x / 100
x^2 = 432 * 100 / 1200
x^2 = 36
x = 6
Answer is Rate of Interest is 6%.

Question 3:

The Simple Interest on sum of money will be 600 after 10 years. If the principal is trebled (# times) after 5 years, what will be total interest?

Solution:

In Simple Interest as long as Principal and Rate of Interest is constant Amount of Interest at any 1 year is constant value.
SI for 10 years = 600 Rs
If Principal trebled after 5 years Total Interest = ??
As 10 years interest is 600 Rs,
One Year Interest = 600 / 10 = 60
One Year Interest is 60 Rs.
10 Years Interest = Interest of 1st 5 Years + Interest of last 5 years after Trebled Principal
As Principal is trebled after 5 years, Interest would also get trebled after 5 years.
[60 * 3 per month]
1st 5 Year Interest = 60 * 5 = 300
Last 5 Year Interest = 60 * 3 * 5 = 900
Total Interest = 300 + 900 = 1200
Answer is Total interest after 10th year is 1200 Rs.

C Interview Questions

String Programs in C

Type 3:

Question 1:

A certain sum of money amounts to 1008 Rs in 2 Years and 1164 Rs in 3.5
years. Find Sum and Rate of Interest?

Solution:

A (after 2 years) = 1008
A (after 3.5 years) = 1164
P = ?
R = ?
1.5 years Interest = 1164 – 1008 = 156 Rs
We will find 1 year interest
A (after 2 years) = 1008
A (after 3.5 years) = 1164
P = ?
R = ?
1.5 years Interest = 1164 – 1008 = 156 Rs
We will find 1 year interest
One year interest = 156 / 1.5
= 104
One year Interest is 104
A = P + SI
Amount after 2 years = 1008
P = 1008 – (2 * 104)
P = 1008 – 208 = 800
Sum is 800
Now we will have to find rate of Interest (R)
SI for 2 years = 2 * 104 = 208
P = 800
N = 2
R = ?
Simple Interest = (P * N * R) / 100
208 = 800 * 2 * R / 100
R = 208 * 100 / (800 * 2)
= 208 / 16
= 13
Rate of Interest is 13%
Answer is Sum is 800 Rs and Rate of Interest is 13%.

Question 2:

A certain sum of money at Simple interest amounts to 1012 in 2.5 years and to 1067.20 in 4 years. The rate of interest per annum is?

Solution:

A (after 2.5 years) = 1012
A (after 4 years) = 1067.20
P = ?
R = ?
1.5 years Interest = 1067.20 – 1012 = 55.20 Rs
We will find 1 year interest
One year interest = 55.20 / 1.5 = 36.8
One year Interest is 36.8
A = P + SI
Amount after 4 years = 1067.20
P = 1067.20 – (4 * 36.8)
P = 1067.20 – 147.20 = 920
Sum is 920 Rs
Now we will have to find rate of Interest (R)
SI for 4 years = 4 * 36.8 = 147.2
P = 928
N = 4
R = ?
Simple Interest = (P * N * R) / 100
147.2 = 920 * 4 * R / 100
R = 147.20 * 100 / (920 * 4)
= 14720 / (920 * 4)
= 1472 / 92 * 4
= 368 / 92
= 4
Rate of Interest is 4%
Answer is Sum is 920 Rs and Rate of Interest is 4%.

Python I

Python II

Python III

Type 4:

Question 1:

A Sum of 1550 Rs is lent out into 2 parts. 1 part at 8% and another at 6%. If the annual income is 106 Rs, find the money at each rate?

Solution:

Here we have 2 Principals, 2 different rate of Interest and Total interest is given.
Let us assume 1 part of Principal (P1) as x.
Other part of Principal(P2) = 1550 – x
R1 = 8%
R2 = 6%
SI = 106
We know total interest but not individual interest.

Total Interest = Interest of Part1 (x) + Interest of Part 2 (1550-x)
Simple Interest = (P * N * R) / 100
106 = (x * 1 * 8) / 100 + (1550 – x) * 1 * 6 / 100
106 = (8x + 9300 – 6x) / 100
10600 = 2x + 9300
2x = 1300
x = 650
Principal 1 (P1) which is at 8% = 650 Rs
P2 = 1550 – x = 1550 – 650 = 900
The answer is Sum given at 8% is 650 Rs and the Sum given at 6% is 900.

Type 5:

Question 1:

At what rate percent per annum will a sum of money double in 16 Years?

Solution:

Similar kind of question can be asked with triple, 8 time of sum etc.
Here we need to understand how much interest we should get to make amount
double.

Assume if Principal is P.
To get sum 2P we will 2P – P = P Simple Interest
So, P = P
SI = P
N = 16
R = ?
Simple Interest = (P * N * R) / 100
P = P * 16 * R / 100
R = 100 / 16 = 6(1/4)
The answer is To get a Sum double in 16 years Rate of Interest should be 6(1/4)%.

Wipro Previous Year Questions

Question 2:

In how many years a sum of money will be double itself at 12 % per annum?

Solution:

A similar kind of question can be asked with a triple, 8 times of sum, etc.
Here we need to understand how much interest we should get to make the amount
double.
Assume if Principal is P.
To get sum 2P we will 2P – P = P Simple Interest
So, P = P
SI = P
R = 12%
N = ?
P = P * 12 * N / 100
N = 100 / 12 = 25 / 3 = 8(1/3)
= 8 Years 4 Months
The answer is to get a Sum double with 12 % annum will be 8 Years and 4 Months.

Cognizant Solutions | CodeGladiators Solutions

Solution 1

Solution 2

Recent Posts