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# Tips And Tricks And Shortcuts For Simple Interest Problems

## Tips, Tricks & Shortcuts To Solve Simple Interest in Aptitude

**Simple interest is the interest calculated on the principal portion of a loan or the original amount. Simple interest does not compound, meaning that lender will only gain interest on the principal amount , and a borrower will never have to pay interest on interest already accrued. Simple Interest = \mathbf{\frac{P * R * T}{100}} **

### Tips & Tricks and Shortcuts for Simple Interest

- Simple Interest=
**\mathbf{\frac{P * R * T}{100}}** - Simple interest is calculated by multiplying the interest rate and principal and number of days.
- Here, are quick and easy tips and tricks on Simple Interest problems learn easily tricks and tips on SI and efficiently in competitive exams and recruitment drive process.
- There are mainly 2 types of questions asked in exams. However, these questions can be twisted to check the students' understanding level of the topic.

### Simple Interest Tricks and Tips and Shortcuts.

- If the interest on a sum of money is
**\frac{1}{x}**of the principal, and the number of years is equal to the rate of interest then rate can be calculated using the formula:**\mathbf{\sqrt{\frac{100}{x}}}**

- The rate of interest for t
_{1}years is r_{1}%, t_{2}years is r_{1}%, t_{3}years is r_{3}%. If a man gets interest of Rs x for (t_{1}+ t_{2}+ t_{3}= n) years, then principal is given by:

\mathbf{\frac{x*100}{r_{1}t_{1}}}**+ r**_{2}t_{2 + }r_{3}t_{3}

- If sum of money becomes x times in t years at simple interest, then the rate is calculated as
**R =**\mathbf{\frac{100(x-1)}{t}}**%**

- If a sum of money becomes x times in t years at simple rate of interest, then the time is calculated as t = \mathbf{\frac{100(x-1)}{R}}

- If an amount P
_{1}is lent out at simple interest of R_{1}% p.a. and another amount of P_{2}at simple interest of R_{2}% p.a, then the rate of interest of the whole sum is given by:**R =**\mathbf{\frac{P_{1}R_{1}+P_{2}R_{2}}{P_{1}+P_{2}}}

### Type 1: Tips and Tricks and Shortcuts To Find Simple Interest

**Question 1. Find the simple interest of Rs 1000 for 10 years at 6% p.a.?**

**Options:**

**A. Rs. 60**

**B. Rs. 6000**

**C. Rs. 600**

**D. Rs. 6**

**Solution: **We know that,

SI = p*r*t/100

SI = 1000*6*10/100

SI = 60000/100

SI = Rs. 600

**Correct option: C**

### Type 2: Simple Interest Tips and Tricks- When Rate of Interest is different for Different Years

**Question 1. If a sum of Rs.25000 is given as loan for a period of 4 years with the interest rates 2%, 4%, 5%, and 6% for the 1st, 2nd, 3rd, and 4th year respectively. What is the total amount that has to be paid at the end of 4 years?**

**Options:**

**A. Rs. 29250**

**B. Rs. 29520**

**C. Rs. 25920**

**D. Rs. 25290**

**Solution: **As this is a case of Simple Interest we add 2% + 4% + 5% and 6% = 17%.

Amount = Principal + Rate of Interest.

Principal is 100% of the amount.

Therefore,

Amount = 100% + 17%.

Therefore Amount = 117%

Amount = (117*25000)/100

=29250

**Correct option: A**

### Type 3: Simple Interest Tips and Tricks and Shortcuts To find the (Rate of Interest, Time period, Principal)

**Question 1. A sum of money becomes 5 times in 20 years. Calculate the rate of interest.**

**Options:**

**A. 20%**

**B. 13%**

**C. 15%**

**D. 25%**

**Solution: **We know that, If sum of money becomes x times in t years at simple interest, then the rate is calculated as

R = 100 (x-1)/t %

R = 100 (5-1)/20

R = 100 (4)/20

R = 400/20

R = 20%

**Correct option: A**

**Read Also – ****Formulas for Simple interest in Aptitude**

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