Simple interest and Compound interest shortcut tricks pdf

In this article we are sharing Simple interest and Compound interest shortcut tricks pdf. Shortcut tricks on Simple Interest and Compound Interest Shortcut Tricks will help you to do Simple Interest and Compound Interest Shortcut Tricks mentally and very quickly. These short tricks do not use any formula and give you the answer within 5 to 10 seconds. We provide solution for the Simple Interest and Compound Interest Shortcut Tricks shortcut tricks for faster mathematical calculation.Compound Interest is the interest calculated on the initial principal and the accumulated interest of previous periods of a deposit or loan.

Simple interest and Compound interest shortcut tricks pdf download links are given at the end of the post

First of all let us discuss the traditional method of solving simple interest question using the formula given below.

Where:

• I. = Simple Interest (साधारण ब्याज)
• P = Principal Amount (मूलधन)
• R = Rate of Interest (ब्याज की दर)
• T = Time (समय)

These are total 4 parameters given in above formula. In commonly asked question the value or the condition for any 3 parameters will be given and we have to find out the value of remaining 4th parameter. We can solve all the questions using this formula but the key problem in exam is of time. Simple Interest questions using above formula become little lengthy.

So to overcome this problem and save your important time in exam we have developed some super awesome short tricks to solve all types of questions of Simple Interest topic just within 5 to 10 seconds. Lets start with a basic example.

Suppose a simple interest is levied on an amount for 5 years at a rate of 10% annually.

So the rate of interest for first year = 10%

Similarly, for second, third, fourth and fifth year = 10% each

So the total rate of interest for all 5 years = 10+10+10+10+10 = 50%

Note: This is simple interest so no interest on interest levies in it. That is why we sum up the rate of interest for all the given years to find our the total interest. Banking and other financial institutions used compound interests which we will discuss in a separate post under Compound Interests Topic. So lets start discussing the short tricks for different types of Simple Interest Questions.

Type 1 of Simple Interest Questions:

Question: In amount of Rs. 5000 was lent for 3 years at rate of 10% annual then find the simple interest.

Solution using Short Trick:

Given that,

Rate of interest = 10% annual.

So the total interest for 3 years = 10 + 10 + 10 = 30%

30% of 5000 =

on solving we get 30% of 5000 = 1500

Hence the Simple Interest is Rs. 1500. 

Type 2 of Simple Interest Questions:

Question: At what annual rate of interest the simple interest of Rs 600 for 10 years will be Rs 120?

Solution using Short Trick:

Given that,

Amount of Simple Interest for 10 years = 120 Rupees

Principal Amount = 600 Rupees

So the percentage of interest levied on Rs. 600 in 10 years will be

= 20%

as 20% interest levied in 10 years, so the Interest levied in one year = 20/10 = 2%

2% is the annual rate of interest which is a required answer.

Type 3 of Simple Interest Questions:

Question: An amount in a period of 5 years become 3/2 times with an annual rate of simple interest. Find the annual rate of interest.

Solution:

Given that,

Compound Money = 3/2 of Principal Money

We should know that, Compound Money = Principal Money + Interest        ………. (1)

Short Trick:

Lets assume principal amount = 100%

So, the Compound Money = 3/2 of 100%

Using Equation (1):

Interest = Compound Money – Principal Money = 150 – 100 = 50%

Here, the interest 50% is for 5 years.

So the rate of annual interest will be = 50/5 = 10% annual.

10% is the annual rate of interest, which is the required answer.

Type 4 of Simple Interest Questions:

Question: An amount was lent on simple interest. So its Simple interest become 3/5 times of principal amount in 3 years. Find the annual rate of interest.

Solution using short trick:

Lets assume principal amount = 100%

So, the simple interest in 3 years will be = 3/5 of 100%

Since, Interest levied in 3 years = 60

so, the annual rate of interest will be = 60/3 = 20%

20% is the annual rate of interest, which is the required answer.

Simple interest and Compound interest shortcut tricks ( Simple Interest ):

Formula:

1) SI = P x R x T/100

2) Principal = Simple Interest ×100/ R × T

3) Rate of Interest = Simple Interest ×100 / P × T

4) Time = Simple Interest ×100 / P × R

5) If rate of Simple interest differs from year to year, then

Simple Interest = Principal × (R1+R2+ R3…..)/100

The four variables in the above formula are:
SI=Simple Interest
P=Principal Amount (This the amount invested)
T=Number of years
R=Rate of interest (per year) in percentage

1). A sum of money is divided into n parts in such a way that the interest on the first part at r₁% for t₁ years, on second part at r₂% for t₂ years, on third part at r₃% for t₃years and so on, are equal. Then the ratio in which the sum is divided in n part is:

1/r₁×t₁: 1/r₂ ×t₂: 1/r₃×t₃

Example:

A sum of Rs 7700 is lent out in two parts in such a way that the interest on one part at 20% for 5 yr is equal to that on another part at 9% for 6 yr. Find the two sums.

Solution:

Here, R1 = 20% R2 = 9%

T1 = 5 yr T2 = 6 yr

By using formula, ratio of two sums  = 1/100 : 1/54 = 27 : 50

Therefore, first part = [27/(27+50)]*7700 = Rs 2700

Second part = [50/(27+50)]*7700 = Rs 5000

 

2). Amount = Principal + S.I = p + [(p x r x t)/100]

Simple interest and Compound interest shortcut tricks ( Compound Interest )

The difference between the amount and the money borrowed is called the compound interest for given period of time

1) Let principal =P; time =n years; and rate = r% per annum and let A be the total amount at the end of n years, then

A = P*[1+ (r/100)]ⁿ;

CI = {P*[1+ (r/100)]ⁿ -1}

2) When compound interest reckoned half yearly, then r% become r/2% and time n become 2n;

A= P*[1+ (r/2*100)]²ⁿ

3) For quarterly

A= P*[1+ (r/4*100)]⁴ⁿ

4) The difference between compound interest and simple interest over two years is given by

Pr²/100²or P(r/100)2

5) The difference between compound interest and simple interest over three years is given by

P(r/100)²*{(r/100)+3}

6) When Rates are different for different years, say R1%, R2%, R3% for 1st, 2nd and 3rd year respectively, Then total amount is given by

P ((1 + R¹)/100) ((1 + R²)/100) ((1 + R²)/100)

7) Present worth of Rs. x due n years hence is given by

x/(1+R/100)

 

1). Interest is compounded half-yearly, therefore,

Example:

Find the compound interest on Rs. 20,000 in 2 years at 4 % per annum, the interest being compounded half-yearly. 

Solution:

Principal = Rs. 20000, Rate = 2 % per half-year, Time = 2 years = 4 half- years

Amount=Rs.21648.64

Compound Interest = Total amount – Principal
= 21648.64 – 20000
= Rs. 1648.64

 

2). If interest is compounded annually,

Example:

Find compound interest on Rs. 8500 at 4 % per annum for 2 years, compounded annually. 

Solution:

We are given:
Principal = Rs. 8500, Rate = 4 % per annum, Time = 2 years

= Rs. 9193.6
Compound Interest = Total amount – Principal
= 9193.6 – 8500
= 693.6
Compound Interest = Rs. 693.6

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