Simple Interest
MCQs Math


Question:     Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $5822 to clear the loan, then find the time period of the loan.


Correct Answer  7

Solution And Explanation

Solution

Given,

Principal (P) = $4100

Rate of Simple Interest (R) = 6% per annum

Amount (A) = $5822

Thus, time (T) = ?

Method (1) Using Formula

Calculation of Simple Interest, when Principal and Amount are given

Formual to Calculate Simple Interest when Principal and Amount are given

We know that, Amount (A) = Principal (P) + Simple Interest (SI)

⇒ Simple Interest (SI) = Amount – Principal

⇒ SI = $5822 – $4100 = $1722

Thus, Simple Interest = $1722

Calculation of the Time using forumula when Amount, Simple Interest and Principal are known

Formula to find the Time (T)

Time (T) = 100 × Simple Interest/Principal × Rate of Interest

⇒ T = 100 × SI/P × R

Thus, Time (T) = 100 × 1722/4100 × 6

= 172200/24600

= 7 years (using formula)

Thus, Time (T) = 7 years (from time taken before calculation)Answer

Calculation of the Time using Unitary Method when Amount, Simple Interest and Principal are known

Here, we have

Principal (P) = $4100

Rate of Simple Interest (R) = 6% per annum

Simple Interest = $1722 (As calculated above by subtracting Principal from the Amount given)

We know that, interest is calculated on the basis of the Principal.

This means Simple Interest for 1 year = Rate of simple interest × Principal

Thus, Simple Interest for 1 year = 6% of Principal

= 6% of $4100

= 6/100 × 4100

= 6 × 4100/100

= 24600/100 = 246

Thus, simple Interest for 1 year = $246

Now,

∵ If the simple Interest is $246, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/246 years

∴ If the simple Interest is $1722, then the time = 1/246 × 1722 years

= 1 × 1722/246 years

= 1722/246 = 7 years

Thus, time (T) = 7 years Answer


Similar Questions

(1) What amount will be due after 2 years if Joshua borrowed a sum of $3950 at a 4% simple interest?

(2) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 5% simple interest?

(3) How much loan did Kenneth borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7700 to clear it?

(4) Find the amount to be paid if John borrowed a sum of $5200 at 9% simple interest for 7 years.

(5) Find the amount to be paid if John borrowed a sum of $5200 at 3% simple interest for 8 years.

(6) If Betty paid $4930 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(7) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 9% simple interest for 3 years.

(8) How much loan did Daniel borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7015 to clear it?

(9) Sandra had to pay $4717 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(10) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 9% simple interest?


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©