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

31. Find the time for which a sum of Rs.1500 is invested at the rate of 8% per annum simple interest if Rs. 1800 is withdrawn after the time for which the investment is done.

ज्ञात कीजिये कि 8% प्रति वर्ष साधारण ब्याज पर निवेश की गई 1500 रुपये की राशि का निवेश कितने समय के लिए किया गया, यदि निवेश का समय पूर्ण होने के बाद 1800 रुपये वापस निकाल लिए जाते हैं।


Option”A” is correct

SI = 1800 – 1500 = Rs. 300

Applying the formula:

300 = (1500 × 8 × T)/100

⇒ T = 2.5

∴ Time of investment = 2.5 years

32.Simple interest for three years for a certain sum at the rate of 15% is ₹ 9000. If the rate of interest becomes 30%, then what will be the simple interest for two years? 

एक निश्चित धनराशि पर 15% की दर से तीन वर्षों के लिए साधारण ब्याज ₹ 9000 है। यदि ब्याज की दर 30% हो जाती है, तो दो वर्षों के लिए साधारण ब्याज क्या होगा?


Option”C” is correct

S.I for 3 years (at R = 15 %) = 9000

⇒ 9000 = (P × 3 × 15)/100

⇒ P = (9000 × 100)/(3 × 15)

⇒ P = 20000

Now, simple interest for two years (at R = 30%)

⇒ S.I = (20000 × 2 × 30)/100

⇒ S.I = 12000

∴ Simple interest for two years (at R = 30%) = ₹12000.

33. The simple interest on a sum of money is (25/343) times the sum. If the number of year is numerically equal to (4/7) times of rate percent per annum, then find rate of interest (upto three decimal place) – 

एक धनराशि पर साधारण ब्याज धनराशि का (25/343) गुना है। यदि वर्षों की संख्या प्रति वर्ष ब्याज की दर प्रतिशत के संख्यात्मक मान के (4/7) गुना के बराबर है, तो ब्याज की दर ज्ञात कीजिये (दशमलव के बाद तीन अंकों तक पूर्णांकित)


Option”B” is correct

Let principal = 343, simple interest = 25, rate = r%, time = (4r/7)

putting the values in given formula:-

⇒ 25 = (343 × 4 × r × r)/(7 × 100)

⇒ r2 = (625/49)

⇒ r = (25/7)%

∴ r = 3.571%

34.Rs. x invested at 9% simple interest per annum for 5 years yields the same interest as that on Rs. y invested at 6.25% simple interest per annum for 8 years. Find x ∶ y.

5 वर्षों के लिए 9% प्रति वर्ष के साधारण ब्याज पर निवेश किये गये x रुपये से उतना ही ब्याज प्राप्त होता है जितना कि 8 वर्षों के लिए 6.25% प्रति वर्ष के साधारण ब्याज पर निवेश किये गये y रुपये पर प्राप्त होता है। x ∶ y ज्ञात कीजिए।


Option”B” is correct

SI1 = (x × 5 × 9)/100 = (45/100) × x

SI2 = (y × 6.25 × 8)/100 = y/2

Equating the two SI, we get,

(45/100) × x = y/2

⇒ x/y = 100/90 = 10/9

 Thus, ratio of x and y, x ∶ y is 10 ∶ 9.

∴ The ratio x ∶ y is 10 ∶ 9.

35. A sum of money at simple interest will become 4 times of itself at 5% per annum S.I. in a certain time. At what rate % per annum; it will become 7 times of itself in the same time.

एक निश्चित समय में साधारण ब्याज पर एक धनराशि 5% प्रतिवर्ष के हिसाब से 4 गुना हो जाएगी। कितनी % ब्याज दर प्रति वर्ष पर उसी समय में यह स्वयं का 7 गुना हो जाएगा।


Option”C” is correct

Let the Principal be 100

⇒ 4 times of Principal = 4 × 100 = 400

A = 400

S.I = A – P = 400 – 100 = 300

Number of years, N = S.I/R (∵ P = 100)

⇒ N = 300/5 = 60 years

When the Principal becomes 7 times, A = 7 × 100 = 700

S.I = A – P = 700 – 100 = 600

Rate of Interest, R = S.I/N

⇒ R = 600/60 = 10%

36. A sum of Rs. 2700 divided in two part in the ratio 5 ∶ 4. If the first part gives for 3.5 years at 1.5% per annum for simple interest and the second part gives for 2.5 years at 1.25% per annum for simple interest. What is the sum of simple interest of both parts?

2700 रुपयों की राशि को दो भागों में 5:4 के अनुपात में विभाजित किया जाता है। यदि पहले भाग को 3.5 वर्ष के लिए प्रति वर्ष 1.5% के साधारण ब्याज दर पर दिया जाता है और दूसरे भाग को 2.5 वर्ष के लिए प्रति वर्ष 1.25% के साधारण ब्याज पर दिया जाता है। तब दोनों भागों के साधारण ब्याज का योग क्या है?


Option”D” is correct

Let the ratio of first part to second part be 5x ∶ 4x

Sum of both part (5x + 4x) = 2700

⇒ 9x = 2700

⇒ x = 300

⇒ 5x = 5 × 300 = 1500

⇒ 4x = 4 × 300 = 1200

As we know,

Simple interest = (P × r × t)/100

According to the question

Sum of simple interest of both parts = [(1500 × 1.5 × 3.5)/100] + [(1200 × 1.25 × 2.5)/100] ⇒ 78.75 + 37.5 = 116.25

∴ The sum of the simple interest is 116.25.

37.A sum lent out at simple interest amount to Rs. 4818 in 1 year and Rs. 6072 in 4 years. The sum and the rate of interest are∶

एक राशि साधारण ब्याज पर निवेश करने पर 1 वर्ष में 4818 रूपये और 4 वर्ष में 6072 रूपये हो जाती है। वह राशि और ब्याज की दर क्या है?


Option”C” is correct

Simple interest of 3 years = 6072 – 4818 = 1254

Simple Interest of 1 year = 1254/3 = 418

Principal = 4818 – 418 = Rs. 4400

⇒ 418 = (4400 × r × 1)/100

⇒ r = (418/4400) × 100 = 9.5%

∴Rate of interest is 9.5%.

38. Two equal sums are lent at 10% and 8% simple interest p.a. respectively, at the same time. The first sum is received 2 years earlier than the second one and the amount received in each case was Rs. 36,900. Each sum was ______.

दो समान राशि क्रमशः 10% और 8% साधारण ब्याज प्रति वर्ष पर समान समय के लिए उधार दी जाती है। पहली राशि दूसरी राशि की तुलना में 2 वर्ष पहले प्राप्त की गई थी और प्रत्येक स्थिति में प्राप्त राशि 36,900 रुपये थी। प्रत्येक राशि ______ थी।


Option”B” is correct

Let year be t year and principal be P

According to the question

(t + 2) × 8 = t × 10

8t + 16 = 10t

10t – 8t = 16

2t = 16

t = 16/2 = 8

According to the question

P + Prt/100 = A

P + (P × 8 × 10) /100 = 36,900

P + 0.8P = 36,900

1.8P = 36,900

P = 36,900/1.8 = 20,500

Short trick:

Let P be 100%, then

100% + 8 × 10% = 36900

180% = 36900

100% = 20,500

39. The simple interest on Rs. x for m years at a rate of r% is equal to the simple interest on Rs. y for n years at the rate of s%, then find x/y.

 r% ब्याज की दर पर m वर्षो के लिए x रुपए की राशि पर लगने वाला साधारण ब्याज s% ब्याज की दर पर n वर्षो के लिए y रुपए की राशि पर लगने वाले साधारण ब्याज के बराबर है, तो x/y ज्ञात कीजिए। 


Option”D” is correct

Simple interest = PRT/100

⇒ (x × r × m)/100 = (y × s × n)/100

⇒ x × r × m = y × s × n

∴ x/y = ns/mr

40. A sum invested at compound interest (compounded annual) amounts to Rs 750 at the end of first year and Rs. 900 at the end of the second year. What is the sum?

चक्रवृद्धि ब्याज (वार्षिक रूप से संयोजित होने वाली) पर निवेश की गयी एक राशि पहले वर्ष के अंत में 750 रुपए और दूसरे वर्ष के अंत में 900 रुपए की राशि हो जाती है। तो राशि क्या है?


Option”B” is correct

Short Trick:

let the amount be Rs. x, then

750/x = 900/750

⇒ x = (750 × 750)/900

⇒ x = 625

Detailed Solution:

A = 750, t = 1 year

As we know,

A = P (1 + r/100)t

⇒ 750 = P (1 + r/100)

⇒ 750/(1 + r/100) = P      —(1)

Again,

A = 900, t = 2 year

As we know,

900 = P (1 + r/100)2

⇒ 900 = P (1 + r/100)2

P = 900/(1 + r/100)2       —(2)

From equation (1) and equation (2)

750/(1 + r/100) = 900/(1 + r/100)2

⇒ (1 + r/100)2/(1 + r/100) = 900/750

⇒ (1 + r/100) = 6/5

⇒ r/100 = 6/5 – 1

⇒ r/100 = 1/5

⇒ r = (1/5) × 100

⇒ r = 20%

Now,

750 = P (1 + 20/100)

⇒ 750 = P × 6/5

⇒ P = 750 × (5/6)

⇒ P = 625