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Simple Interest Shortcut Tricks and Formulas with Examples

Simple Interest Shortcut Tricks  & Formulas – Practice Problems

By using this simple trick on Simple Interest problems, we can able to solve any to any problem in this topic and get answers very quickly than using normal methods.

Simple Interest shortcut Trick – Speed Maths Tricks

While solving simple interest problems by using the percentage method,
Always assume principle P = 100%,
Simple Interest (SI) = (Time × Rate) %.
Total Amount (A) = P + SI = 100% + SI%.
Steps to Solve:

  • We have to analyze them in terms of the above process and assume the principal amount as 100%.
  • If 100% is this much then x% is how much, like this, we have to analyze and solve it by using cross multiplying
    100% = …
    x% =?

For better understanding watch the video given below explained clearly in a step by step process with examples.
And At Some places use below  SI formulae


Simple Interest Shortcut Formulas With Examples for Bank Exams

  1. Simple Interest = PTR/100, (P=Principle Amount, T=Time, R=Rate).
  2. Amount = Principal + Interest
  3. Amount = P ( 1 + rt)
  4. The annual payment that will discharge a debt of ARs/- in ‘t’ years at the rate of interest r% per annum.

Then Payment = (100A) / [(100t )+[(rt(t-1)]/2].

5. Sum = (100I)/(r1t1+r2t2+….)

6. If a sum of money becomes x times in ‘t’ years at simple interest. Then Rate = [[100(x-1)]/t]%.

7. Principle = 100A/100+RT.

8. Sum= [Interest difference/(r1t1-r2t2)]*100.

9. If a sum amounts to ‘A1’ in t1 years and ‘A2’ in t2 years. Then Rate of Interest = 100[A1-A2]/ [A1T2-A2T1].

Simple Interest Practice Problems – SI formulas and shortcuts

 Problem 1: Simple Interest on an amount after 24 months at the rate of 2% per quarter is 960. What is the sum?

Sol: R= 2% per quarter.
=(2% * 4)per  year. = 8 % p.a.
Simple Interest (S.I.)=1st year+ 2nd year=  8%+ 8%= 16%
Here understand the logic i.e.  16% amount à960
Then (sum means 100%)so for 100% à?
With cross multiplication, Sum= 100*960/16=6000.

Problem 2: The simple interest of money is Rs.300 after 5 years. In the next 5 years, If the principle is tripled what will be the total interest at the end of the 10th year?

Sol: 1st 5 years, SI = 300.
Next 5 years à New P| = 3P
New SI| = 3 SI
= 3 *300 =900.
Total Interest = 300+900. = 1200.

Problem 3: Varun borrows 1500 Rs. From a lender. He pays interest at the rate of 12% p.a. for one loan and a rate of 14 % for another loan. How much does he borrow at 12% p.a? If the interest paid at the end of the year is 186 Rs.

Sol: Given, SI 1 + SI 2=186.    P1 is 12% p.a.        P2 is at 14% p.a.
And  P1 +P2= 1500  àequation 1
From above information 12%of P1 +14% of P2 =186      àequation 2.
Solve these 2 equations 1&2 we get P2=300.
And P1 = 1200.


Click Here For More Simple Interest Problems Using Shortcut MethodsBank Exam Tips and Tricks

In the below video, the SI problems are solved using the above formula and shortcut tricks and have been explained clearly step by step.

Once you watch the below video and practice the problems given here.

Simple Interest Practice Problems: Use above SI formulas & Shortcut tricks

1. If a sum doubles itself in 10 years at simple interest. What must be the rate of Interest per anum?

  • 30%
  • 10%
  • 5%
  • 18%.

2. On What sum, invested at the simple Interest rate of 10% per anum for 5 years will the interest be equal to Rs.500?

  • 1000
  • 3000
  • 1500
  • 2000

3. A Simple Interest, a sum amounts to Rs.3360 in 6 years and Rs.3400 in 7 years. What does it amount to in 9 years?

  • 3450
  • 3560
  • 3480
  • 4000

4. The simple interest on a sum of money invested for 6 years is Rs.1500. If after two years, the interest rate is doubled, what will the interest be?

  • 3000
  • 2400
  • 2500
  • 2350

5. If Rs.5800 is divided into two parts, such that the simple interest obtained on the first part at the rate of 7% per anum for 2 years is equal to the simple interest earned on the second part at the rate of 5% for three years. What is the first part?

  • 3000
  • 4500
  • 5000
  • 3450

6. A moneylender lent Rs.400 for two years and Rs.200 for 3 years at the same rate of simple interest and received an Rs.70 as interest. What was the rate of interest per anum?

  • 4%
  • 6%
  • 5%
  • 7%

7. At simple interest, a sum amounts to Rs.3360 in 6 years. And to Rs. 3400 in 7 years. What does it amount to in 9 years?

  • 3560
  • 3480
  • 5000
  • 4000

 

8. The Simple Interest on a certain sum of money at the rate of 10% per anum for 3 years and 5 years differs by Rs.1000, What is the sum?

  • 2000
  • 5000
  • 4000
  • 6000

 

9. When the rate of interest on a loan is increased from 4% and 5% p.a… The interest is Rs.1.11 more per month than before. What is the amount of the loan?

  • 1232
  • 1332
  • 1350
  • 1450

 

10. Ravi and Raju invested Rs.2000 and Rs.3000 at the simple interest rate of 5% and 4% per anum respectively in two banks. What is the difference in the simple interest earned by them after 5 years?

  • 200
  • 100
  • 500
  • 130


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