Simple Interest
MCQs Math


Question:     Anthony took a loan of $6600 at the rate of 10% simple interest per annum. If he paid an amount of $12540 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $6600

Rate of Simple Interest (R) = 10% per annum

Amount (A) = $12540

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 = $12540 – $6600 = $5940

Thus, Simple Interest = $5940

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 × 5940/6600 × 10

= 594000/66000

= 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) = $6600

Rate of Simple Interest (R) = 10% per annum

Simple Interest = $5940 (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 = 10% of Principal

= 10% of $6600

= 10/100 × 6600

= 10 × 6600/100

= 66000/100 = 660

Thus, simple Interest for 1 year = $660

Now,

∵ If the simple Interest is $660, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/660 years

∴ If the simple Interest is $5940, then the time = 1/660 × 5940 years

= 1 × 5940/660 years

= 5940/660 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) How much loan did Emily borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7425 to clear it?

(2) Find the amount to be paid if Mary borrowed a sum of $5050 at 8% simple interest for 7 years.

(3) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 9% simple interest?

(4) Find the amount to be paid if David borrowed a sum of $5400 at 4% simple interest for 8 years.

(5) Calculate the amount due if Thomas borrowed a sum of $3800 at 10% simple interest for 4 years.

(6) Calculate the amount due if Christopher borrowed a sum of $4000 at 8% simple interest for 4 years.

(7) Calculate the amount due if Robert borrowed a sum of $3100 at 9% simple interest for 4 years.

(8) Find the amount to be paid if Robert borrowed a sum of $5100 at 5% simple interest for 7 years.

(9) Michelle had to pay $5395.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(10) Find the amount to be paid if Sarah borrowed a sum of $5850 at 6% simple interest for 8 years.


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