At what rate percent per annum will a sum of Rs 3600 become Rs 4500 in 10 years at simple interest?

Given :

Principal $P = Rs. 4500$

Amount $A = Rs. 5715$

Time $T = 3$ years

To do :

We have to find the rate of interest.

Solution :

Let the rate percent be R.

We know that,

$Amount (A) = Principal (P) + Simple Interest (SI)$

$Simple Interest (SI) = Amount (A) - Principal (P)$

                                   $= Rs. (5715 - 4500)$

                                   $= Rs. 1215$

$SI = \frac{PRT}{100}$

Therefore,

$Rs. 1215 = \frac{(4500 \times R \times 3)}{100}$

$Rs. 1215 = 45 \times R \times 3$

$R = \frac{1215}{(45\times3)}$

$R = 9$

The rate percent is 9%. 

A certain sum at 20% per annum simple interest becomes Rs. 3600 in 3 years. In how many years the principle becomes Rs. 4500 at the same rate of interest?

1. 4 years
2. 5 years
3. 6 years
4. 7 years

Answer (Detailed Solution Below)

Option 2 : 5 years

Free

150 Questions 150 Marks 150 Mins

Given:

Rate = 20%

Amount = Rs. 3600 and T = 3 years

Concept:

Simple interest is the interest calculated on the principal portion of the loan or the original contribution to the saving account.

Formula Used:

Simple Interest = (P × R × T)/100

Amount = Principal + Interest

Calculation: 

Let the principal be 'P' 

⇒ Simple interest = 3600 - P

⇒ 3600 - P = (P × 20 × 3)/100

⇒  3600 - P = 3P/5

⇒ 18000 - 5P = 3P

⇒ 8P = 18000

⇒ P = 18000 ÷ 8 = 2250

Now, When P = Rs. 2250, amount = Rs. 4500 and rate = 20%

Simple interest = 4500 - 2250 = Rs. 2250

Let time be T

⇒ 2250 = (2250 × 20 × T)/100

⇒ T = 5 years

∴ The time is 5 years in which principle become Rs. 4500 at 5%.

Last updated on Sep 26, 2022

The Uttar Pradesh Basic Education Board (UPBEB) is all set to invite fresh applications for the UP SUPER TET (Teacher Eligibility Test) Exam. The said exam is conducted to recruit candidates for the post of Assistant Teacher & Principal in Junior High Schools across the state of Uttar Pradesh. The vacancy is expected to be somewhere around 17000. The minimum eligibility criteria for the Assistant Teacher posts is graduation whereas for the posts of Principal it shall be graduation accompanied by 5 years of teaching experience. The willing candidates can go through the UP SUPER TET Syllabus and Exam Pattern from here.

Let's discuss the concepts related to Interest and Simple Interest. Explore more from Quantitative Aptitude here. Learn now!

 At what rate of interest will a sum of Rs. 4500 amounts to Rs. 6525 at simple interest for 5 years ?

1. 9%
2. 5%
3. 10%
4. 11%

Answer (Detailed Solution Below)

Option 1 : 9%

Given:

Principal = Rs. 4500

Amount = Rs. 6525

Time = 5 years

Concept used:

Simple interest

Calculation:

\({\rm{si = }}\frac{{{\rm{P}} \times {\rm{R}} \times {\rm{T}}}}{{100}}\)

Principal + interest = Amount

Interest = Amount - Principal

Interest = 6525 - 4500 = 2025

Interest for 5 years = Rs. 2025

Interest for 1 year = 2025/5 = Rs. 405

\({\rm{Rate = }}\frac{{{\rm{Interest}}\; \times \;{\rm{100}}}}{{{\rm{Principal}}\; \times \;{\rm{Time}}}}\)

Rate = \(\frac{{405\; \times \;100}}{{4500}} = 9\% \)

Stay updated with the Quantitative Aptitude questions & answers with Testbook. Know more about Interest and ace the concept of Simple Interest.

At what rate percent per annum will a sum of rupees 3600 become 4500 in 10 years at simple interest?

At what rate percent per annum will ₹ 3600 amounts to ₹ 4320 in 4 years?

At what rate percentage per annum simple interest will Rs 4500 amounts to Rs 5715 in 3 years?

In what time will the interest on 3600 at the rate of 10% be equal to the interest on 1800 at the rate of 12.5% in 4 years?