Simple Interest
MCQs Math


Question:     Mary took a loan of $4100 at the rate of 8% simple interest per annum. If he paid an amount of $7052 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $4100

Rate of Simple Interest (R) = 8% per annum

Amount (A) = $7052

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 = $7052 – $4100 = $2952

Thus, Simple Interest = $2952

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 × 2952/4100 × 8

= 295200/32800

= 9 years (using formula)

Thus, Time (T) = 9 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) = 8% per annum

Simple Interest = $2952 (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 = 8% of Principal

= 8% of $4100

= 8/100 × 4100

= 8 × 4100/100

= 32800/100 = 328

Thus, simple Interest for 1 year = $328

Now,

∵ If the simple Interest is $328, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/328 years

∴ If the simple Interest is $2952, then the time = 1/328 × 2952 years

= 1 × 2952/328 years

= 2952/328 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) In how much time a principal of $3100 will amount to $3410 at a simple interest of 5% per annum?

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

(3) How much loan did Jeffrey borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9360 to clear it?

(4) Elizabeth took a loan of $4900 at the rate of 8% simple interest per annum. If he paid an amount of $8820 to clear the loan, then find the time period of the loan.

(5) If Joshua paid $5488 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(6) Find the amount to be paid if Joseph borrowed a sum of $5700 at 3% simple interest for 8 years.

(7) Calculate the amount due if Mary borrowed a sum of $3050 at 7% simple interest for 4 years.

(8) Kenneth had to pay $5450 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(9) Calculate the amount due if Jennifer borrowed a sum of $3250 at 4% simple interest for 3 years.

(10) Find the amount to be paid if William borrowed a sum of $5500 at 2% simple interest for 8 years.


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