Find Compound Interest Tricks


Shortcut tricks on compound interest are one of the most important topics in exams. Time takes a huge part in competitive exams. If you know time management then everything will be easier for you. Most of us miss that part. We provide examples on Compound Interest shortcut tricks here in this page below. These shortcut tricks cover all sorts of tricks on Compound Interest. We request all visitors to read all examples carefully. These examples here will help you to better understand shortcut tricks on compound interest.

Before doing anything we recommend you to do a math practice set. Then find out twenty math problems related to this topic and write those on a paper. Solve first ten math problems according to basic math formula. You also need to keep track of Timing. After finish write down total time taken by you to solve those ten maths. Now read our examples on compound interest shortcut tricks and practice few questions. After doing this go back to the remaining ten questions and solve those using shortcut methods. Again keep track of timing. The timing will be surely improved this time. But this is not all you need. You need to practice more to improve your timing more.

You all know that math portion is very much important in competitive exams. That doesn’t mean that other topics are less important. But only math portion can leads you to a good score. You can get good score only by practicing more and more. All you need to do is to do math problems correctly within time, and you can do this only by using shortcut tricks. But it doesn’t mean that without using shortcut tricks you can’t do any math problems. You may have that potential to do maths within time without using any shortcut tricks. But other peoples may not do the same. Here we prepared compound interest shortcut tricks for those people. Here in this page we try to put all types of shortcut tricks on Compound Interest. But it possible we miss any. We appreciate if you share that with us. Your little help will help so many needy.

 

Find Compound Interest using Tricks
In case of Compound Interest the interest is vary according time to time. But, at the first year it is equal to:

  • Compound Interest = Simple Interest

 

But, after that year it is increases. So, then we need to find Compound Interest using formula. This type of problem are given in Quantitative Aptitude which is a very essential paper in banking exam. Under below given some more example for your better practice.

 

 

Few examples of Compound Interest
Here Principal amount, Rate of percent and Time is given. You need to find the Compound interest using formula and tricks.

 


Example #1
What would be compound interest obtained on an amount of Rs.8000/- at the rate of 10% per annum after 2 years?

Show Answer

Simple Method
For the First year interest will be:
8000 x 10 / 100
= Rs.800/-

For the Second year interest will be:
( Principal Amount + First year interest ) x 10 / 100
= ( 8000 + 800 ) x 10 / 100
= 8800 x 10 / 100 = Rs.880/-

So, After 2 years compound interest will be ( 800 + 880 ) = Rs.1680/-.


Example #2
What would be the compound interest to be obtained on an amount of Rs.8000/- at the rate of 10% per annum after 2 years?

Show Answer

Using Formula
P = Principal Amount
R = Rate of Interest
N = Number of Years

CI = P [(1 + R / 100)N – 1]
8000 x [(1 + 10 / 100)2 – 1]
= Rs.1680/-


Example #3
Raju invested an amount of Rs.8460/- at 6% per annum for 2 years. What approx amount would he obtain at the end of two years?

Show Answer

8460 x 106 x 106 / 100 x 100 = 9505/- (approx).

Example #4
What will be the compound interest on a sum of Rs.6500/- at the rate of 6% per annum for 2 years?

Show Answer

(6500 x 53 x 53 / 50 x 50 -1)
= Rs. 803.4/-

Example #5
Find the compound interest of Rs.18000 at 5% per annum in 3 years.

Show Answer

18000 x 21 x 21 x 21 / 20 x 20 x 20 = 20837.25

Example #6
Find the compound interest obtained on an amount Rs.8000/- at the rate of 12% per annum for 2 years.

Show Answer

CI = 8000 [ (112 / 100)2 – 1 ]
= Rs.2035.2/-

Example #7
The simple interest deposited on sum of certain principle is Rs.8400/- for 7 years at the rate of 12% per annum. What should be the CI deposited on that principle at the rate of 6% per annum in 2 years?

Show Answer

X x 7 x 12 / 100 = 8400
X = Rs.10000/-

So, Compound Interest is = ( 10000 x 105 x 105 / 100 x 100 ) – 10000
= 11236 – 10000
= Rs.1236/-


Example #8
Principal is 15000 at rate percent 4% per annum for 2 years and compound annually. Find the CI.

Show Answer

We apply the formula to obtain CI is:
CI = P [(1 + R / 100)N – 1]
P = 15000
R = 4%
N = 2

CI = 15000 x [( 1 + 4 / 100)2 – 1]
= 15000 x [ 26 x 26 / 25 x 25 – 1] [ as we put down (26 / 25)2 ]
= 15000 x 51 / 625
= 1224.


Example #9
Simple Interest accrued on an amount of Rs.22500/- at the end of 3 years is Rs.10800/-. What would be the Compound Interest accrued on the same amount at the same rate at the end of 2 years?

Show Answer

Here is given,
Amount = 22500
Time = 3
SI = 10800
So, we need to find Rate percent.

We know SI = P x T x R / 100
10800 = 22500 x R x 3 / 100
R = 1080000 / 67500
= 16%
So, Rate of percent = 16%.

Compound Interest accrued on the same amount at the same rate at the end of 2 years will be:
CI = 22500 x (116 / 100 x 116 / 100 – 1 )
= 22500 x( 116 x 116/ 10000 – 1)
= 22500 x( 13456 / 1000) – 1
= 22500 x (1.3456 – 1)
= 22500 x 0.3456
= 7776

So the CI at the end of 2 years will be Rs.7776/-.


Example #10
What would be the compound interest on an amount Rs.6000/- at the rate 12% per annum for 2 years?

Show Answer

= 6000 [ (112 / 100)2 – 1]
= 6000 x 2544 / 10000
= 1526.4

Example #11
What will be the compound interest on a sum of Rs.4800/- at the rate of 6% per annum for 2 years?

Show Answer

Compound Interest = P [ 1 + R / 100 ]n – 1
4800 x [( 1 + 6 / 100 )2 – 1]
4800 x [ 53 x 53 / 50 x 50 – 1 ]
= 593.28

So, the compound interest is Rs.593.28/-.


Example #12
What would be the compound interest obtained on an amount of Rs.1600/- at the rate of 8% per annum after 2 years?

Show Answer

Amount = SI + Principal
Compound Interest = P ( 1 + R / 100)N – 1600
1600 ( 1 + 8 / 100 )2 – 1600
( 1600 x 27 x 27 / 25 x 25 ) – 1600
= ( 1866.24 – 1600 )
= 266.24

So, the compound interest would be Rs.266.24/-.


Example #13
What would be the compound interest obtained on an amount of Rs.6000/- at the rate of 10% per annum after 2 years?

Show Answer

6000 x [(1 + 10 / 100)]n – 1
= 6000 x [(11 / 10 )2 – 1]
= 6000 x 21 / 100
= 1260

So, the compound interest would be Rs.1260/-.


Example #14
What would be the compound interest obtained on an amount of Rs.8850/- at the rate of 12% per annum after 2 years?

Show Answer

Principal = 8850
Rate = 12
Time = 2 years

Amount = 8850 ( 1 + 12 / 100 )2
= 8850 x 28 x 28 / 25 x 25
= 11101.44

So, CI = ( 11101.44 – 8850 ) = Rs.2251.44/-


Example #15
What would be the compound interest obtained on an amount of Rs.7500/- at the rate of 6% per annum after 2 years?

Show Answer

Amount = 7500
Rate = 6
Time = 2 years

= 7500 [ 106 x 106 / 100 x 100 ] – 7500
= 7500 x 11236 / 10000 – 7500
= 8427 – 7500
= 927

So, compound interest after 2 years would be Rs.927/-.


Example #16
In after the period of 2 years, what would be the compound interest get on a principal amount of Rs.6400/- at the rate of 8% per annum.

Show Answer

In first year it’s always same = 6400 x 8 / 100 = 512
In Second year compound interest is 512 + 40.96. [ i.e, 512 x 8 / 100 = 40.96 ]
So, total compound interest is 512 + 512 + 40.96 = 1064.96

Example #17
What compound interest accrued on an amount of Rs.18000/- at the rate of 10% per annum for the 2 years?

Show Answer

Formula: A = P( 1 + R / 100 )N
= 18000 ( 1 + 10 / 100 )2
= 18000 x 22 x 22 / 20 x 20
= 21780

So, compound interest after 2 years would be ( 21780 – 18000 ) = Rs.3780/-.


More Shortcut tricks on Simple and Compound Interest

 

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11 comments

    • suryakant sahoo says:

      p.a.=6400
      r=8
      for 1st year t=1
      s.i.=6400*1*8/100=512

      for second year u need 6400’s s.i. + 512’s s.i.
      for one year now t=1

      6400’s s.i. for one year=512
      512,s =512*1*8/100=40.96
      then add all

    • harish says:

      to determine compountd interest directly use minus 1 else the answer we get is amount.so to calculate directly CI they used
      amount=p(1+r/100)^n
      compound interest =p((1+r/100)-1)^n

  1. Ajay says:

    compound interest simple method fpr example
    P.a=10000
    R=10%
    T=3yr

    solve:
    1000*3=3000
    100*3=300
    10*1=10
    total =3310
    compound interest=3310Ans

  2. Roopa says:

    (CI)2 yrs -( SI)2 yrs =12,R%=20%,P=?

    (SI)2 yrs=20+20=40% ;
    (CI)2 yrs=(20+20+(20*20/100))% (shortcut)
    =(40+(400/100))%
    =(40+4)%
    =44%
    (CI)2 yrs -(SI)2 yrs =44-40 =4
    we know that, P=(CI)2 yrs -(SI)2 yrs
    given that, (CI)2 yrs -(SI)2 yrs =12

    P = 44/100 -40/100
    P=100
    we need to multiply by 3 becoz in questn given 12
    P=300

  3. Roopa says:

    If % increases or a% and b% overall % increases is given by (a+b+ab/100)%

    ex:20% increase for 2 yrs is
    =( 20+20+20*20/100)%=44%

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