Top140 Simple Interest Questions For 100% Free [Effective]

Welcome to this guide on simple interest questions. For many, the topic of interest can be confusing, especially when diving into the world of finance. If you’ve ever wondered about simple interest questions or how to work with simple interest problems, you’re in the right place.

We frequently come across the word “interest” in our daily lives, especially when talking about money. There are different types of interests, with simple interest and compound interest being the most common. Through this article, we’ll be focusing extensively on simple interest questions and simple interest problems.

For those who prefer understanding in their native language, we’ve got simple interest questions in Hindi and the simple interest formula in Hindi. Our goal is to make simple interest in Hindi understandable for everyone.

But, what exactly is the simple interest formula? It’s a method used to figure out how much interest you’ll earn or owe over a period of time. The formula is straightforward: SI = PTR/100, where P is the Principal amount, T is the Time (in years), and R is the Interest rate.

Moreover, it’s essential to know that simple interest questions and simple interest and compound interest questions often appear in competitive exams. Whether it’s SSC, SBI, Railways, or any other state exams, mastering simple interest and compound interest questions can give you an edge. If you have a clear concept of ratio and percentage, you’ll find that tackling simple interest questions becomes much more manageable.

So, let’s dive deeper into simple interest questions and help you master the topic, whether in English or simple interest in Hindi. Happy learning!

Top140 Simple Interest Questions

61. A sum of Rs. 825 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of Rs. 412.50 more is lent but at the rate twice the former. At the end of the year, Rs. 35.75 is earned as interest from both the loans. What was the original rate of interest?

825 रुपये की राशि एक निश्चित ब्याज दर पर वर्ष की शुरुआत में उधार दिया जाता है। 8 महीने के बाद, 412.50 रुपये और उधार दिया जाता है लेकिन पूर्व की तुलना में दोगुनी दर पर। वर्ष के अंत में, दोनों ऋणों से ब्याज के रूप में 35.75 रुपये अर्जित किया जाता है। मूल ब्याज दर क्या थी?


Option”B” is correct

Interest for 8 months = (825 × R × 8)/(12 × 100) = 5.5R

Sum for last 4 months = Rs. (825 + 412.50) = Rs. 1237.50

Rate of interest for last 4 months = 2R

Interest for last 4 months = (1237.5 × 2R × 4)/(12 × 100) = 8.25R

Total interest for 1 year = 5.5R + 8.25R = 13.75R

⇒ 13.75R = 35.75

⇒ R = 35.75/13.75 = 2.6%

∴ The original rate of interest is 2.6%

62.INR 3000 is invested at 7% simple interest. If half of the interest is added to the principal after one year then after approximately how many years will it be INR 3189

3000 रुपए की राशि को 7% साधारण ब्याज की दर से निवेश किया गया है। यदि एक वर्ष के बाद आधे ब्याज को मूलधन में जोड़ दिया जाता है तो लगभग कितने वर्षों के बाद यह धनराशि 3189 हो जाएगी?


⇒ SI = PRT / 100 = 3000 × 7 × 1 / 100 = 210

Now,

⇒ half of interest is added to principal amount,

3000 + 105 = 3105

⇒ Final amount = 3189

⇒ Interest = 3189 – 3105 = 84

Now,

⇒ 84 = 3105 × 7 × t / 100

⇒ t = 8400 / 21735

⇒ t = 0.386 ≈ 0.4

Hence,

∴ After 1 + 0.4 = 1.4 years 

ALTERNATE METHOD 

Let the time taken be x.

According to the question:

⇒ (3000 + 1/2 × 3000 × 7 × 1/100) × x × 7/100 = 84

⇒ x = 0.386 ≈ 0.4

Total Time = 1 + 0.4 = 1.4 years

∴ The total time is 1.4 years.

63. Find the time in which the simple interest on a sum of money becomes 5/8th of the principal at 12.5 % per annum interest rate?

वह समय ज्ञात कीजिए जिसमें एक धनराशि पर साधारण ब्याज 12.5 प्रतिशत प्रति वर्ष की दर से मूलधन का 5/8 गुना हो जाता है?


Option”C” is correct

Let the principal be ‘P’ 

So, the simple interest = 5P/8 

According to the question:

⇒ 5P/8 = (P × 12.5 × T)/100

⇒ T = 5 years

64. A certain sum amounts to Rs. 38250 in 5 years and Rs. 34000 in 4 years. The rate of interest is ____ . The Simple Interest calculated on same amount and same rate for 3 years is Rs. ____ .

एक निश्चित राशि 5 वर्षों में 38250 रूपए और 4 वर्षों में 34000 रूपए हो जाती है। ब्याज की दर ____ % है। समान राशि पर समान दर पर 3 वर्षों के लिए गणना किया गया साधारण ब्याज ____ रूपए है।


Option”A” is correct

Let Principal = P, Rate = R% per annum, Time = N years

Simple Interest = (P × N × R)/100

Given,

Simple Interest for a year = 38250 – 34000 = Rs. 4250

Simple interest for 3 years = 4250 × 3 = Rs. 12750

Simple interest in 4 years = 4250 × 4 = Rs. 17000

Principal amount = 34000 – 17000 = Rs. 17000

Rate of interest = (17000 × 100)/(17000 × 4)

Rate of interest = 25%

Shortcut Trick

Since simple interest remains same for each year

Simple Interest for a year = 38250 – 34000 = Rs. 4250

Simple interest for 3 years = 4250 × 3 = Rs. 12750

only option 1 satisfies the above condition

65. The simple interest and the true discount on a certain sum for a given time and at a given rate are Rs 95 and Rs 90 respectively. The sum is –

एक निश्चित मूलधन पर दिए गये समय और दिए गये ब्याज दर पर साधारण ब्याज और वास्तविक छूट क्रमशः 95 रुपए और 90 रुपए है। वह मूलधन है – 


Option”A” is correct

Let the amount be Rs. x and rate is r%

For Simple interest

⇒ x × r/100 = 95

⇒ x r = 9500      —-(1)

For true Discount

⇒ (x – 90)× r/100 = 90

⇒ x r – 90r = 9000      —-(2)

From Equation (1) and (2), we get

⇒ 9500 – 90r = 9000

⇒ 90r = 500

⇒ r = 50/9

Putting r = 50/9 in the equation (1)

⇒ x = 9500 × 9/50

⇒ Rs. 1710

∴ The sum is Rs. 1710.

66.A certain principal amounts to Rs. 15000 in 2.5 years and to Rs. 16500 in 4 years at the same rate of interest. Find the rate of interest.

एक निश्चित मूलधन 2.5 वर्ष में 15000 रु और 4 वर्षों में 16500 रु हो जाता है। ब्याज की दर ज्ञात कीजिए।


Option”B” is correct

SI of 1.5 years = 16500 – 15000 = 1500

⇒ SI of 1 years = 1500/1.5 = 1000

⇒ SI of 2.5 years = 1000 × 2.5 = 2500

Principal = 15000 – 2500 = 12500

As we know,

SI = Prt/100

⇒ 1000 = (12500 × r × 1)/100

⇒ r = 1000/125

∴ r = 8%

67.What will be the compound interest (nearest to integer) on a sum of Rs. 25,000 for 2 years at 12% p.a., if the interest is compounded 8 monthly?

₹ 25,000 की धनराशि पर 2 वर्षों के लिए 12% प्रति वर्ष की दर से चक्रवृद्धि ब्याज (पूर्णांक के निकट तक) क्या होगा, यदि ब्याज 8 माह में संयोजित होता है?


Option”B” is correct

Short trick∶

⇒ 25000 × (8/100) = 2000 × 3 = 6,000

⇒ 2000 × (8/100) = 160 × 3 = 480

⇒ 160 × (8/100) = 12.8

∴ Total interest = 6000 + 480 + 12.8 = Rs. 6492.8

Detailed solution∶

Total sum = Rs. 25000

Rate for 12 months = 12%

⇒ Rate for 8 months = 8% and Time (24 months)/8 = 3

⇒ Amount = 25000 × (27/25) × (27/25) × (27/25) = Rs. 31,492.8

∴ Required Interest = 31,492.8 – 25,000 = Rs. 6,492.8

68. If Rs. 10000 amounts to Rs. 12100 in a year when compounded half yearly. Find the compound interest at the same rate for 2 years calculated annually on the same amount.

यदि 10000 रुपए की धनराशि एक वर्ष में अर्धवार्षिक चक्रवृद्धि ब्याज की दर से 12100 रुपए हो जाती है, तब समान धनराशि पर 2 वर्षों के लिए समान वार्षिक ब्याज की दर से चक्रवृद्धि ब्याज की गणना कीजिये।


Option”A” is correct

Suppose Principal = P, Rate = R% per annum, Time = n years

When interest is compound annually∶

Amount = P[1 + (R/100)]n

Given,

For half yearly, N = 1 × 2 = 2 and r = R/2

⇒ 12100 = 10000(1 + r/100)2

⇒ 1 + r/100 = 1.1

⇒ r/100 = 0.1

⇒ r = 10%

⇒ R = 10 × 2 = 20%

Compound interest for two years calculated annually

= 10000(1 + 20/100)– 10000 = (10000 × 1.2 × 1.2) – 10000 = 4400

Compound Interest calculated annually is Rs. 4400.

69. The compound interest on a certain sum of money at 21% for 2 years is Rs. 9,282. Its simple interest (in 2 years) at the same rate and for the same period is: 

एक निश्चित राशि पर 2 साल के लिए 21% से चक्रवृद्धि ब्याज 9282 रुपए होता है, समान दर पर और समान अवधि के लिए इया राशि का साधारण ब्याज (2 साल में) है:


Option”D” is correct

Given

r = 21%

Compound interest rate for 2 years = (21 + 21 + 21 × 21/100) = 46.41 %

Let certain sum be P

∴ P × 46.41% = 9282

⇒ P × (4641/100 × 100) = 9282

⇒ P = Rs. 20000

Again for SI

P = 20000

r = 21%

t = 2 year

∴ SI = P × r × t /100 = 20000 × 21 × 2/100 = Rs. 8400

70. A sum of Rs. 1000 is invested on compound interest (compounding annually) for three years. If the rate of interest is 10% per annum for the first two years and 50% per annum for the third year, then what will be the interest?

1000 रुपए की एक राशि को तीन वर्षो के लिए चक्रवृद्धि ब्याज (वार्षिक रूप से संयोजित होने पर) पर निवेश किया गया। यदि ब्याज की दर पहले दो वर्षो के लिए प्रति वर्ष 10% है और तीसरे वर्ष के लिए प्रति वर्ष 50% है, तो ब्याज क्या होगी?


Option”D” is correct

Amount after 3 years = 1000 × 110% × 110% × 150%

⇒ Amount = 1000 × 11/10 × 11/10 × 3/2

⇒ Amount = Rs. 1815

So, the interest earned = Amount – Principal

⇒ The interest earned = 1815 – 1000

∴ The interest after 3 years will be Rs. 815