Simple Interest
MCQs Math


Question:     Mary took a loan of $4100 at the rate of 9% simple interest per annum. If he paid an amount of $6314 to clear the loan, then find the time period of the loan.


Correct Answer  6

Solution And Explanation

Solution

Given,

Principal (P) = $4100

Rate of Simple Interest (R) = 9% per annum

Amount (A) = $6314

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 = $6314 – $4100 = $2214

Thus, Simple Interest = $2214

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 × 2214/4100 × 9

= 221400/36900

= 6 years (using formula)

Thus, Time (T) = 6 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) = 9% per annum

Simple Interest = $2214 (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 = 9% of Principal

= 9% of $4100

= 9/100 × 4100

= 9 × 4100/100

= 36900/100 = 369

Thus, simple Interest for 1 year = $369

Now,

∵ If the simple Interest is $369, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/369 years

∴ If the simple Interest is $2214, then the time = 1/369 × 2214 years

= 1 × 2214/369 years

= 2214/369 = 6 years

Thus, time (T) = 6 years Answer


Similar Questions

(1) Find the amount to be paid if Thomas borrowed a sum of $5800 at 4% simple interest for 8 years.

(2) If Thomas borrowed $3800 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

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

(4) Margaret took a loan of $6700 at the rate of 8% simple interest per annum. If he paid an amount of $10988 to clear the loan, then find the time period of the loan.

(5) In how much time a principal of $3000 will amount to $3600 at a simple interest of 5% per annum?

(6) Calculate the amount due if Christopher borrowed a sum of $4000 at 5% simple interest for 4 years.

(7) Calculate the amount due if Michael borrowed a sum of $3300 at 7% simple interest for 3 years.

(8) Thomas took a loan of $5600 at the rate of 9% simple interest per annum. If he paid an amount of $9128 to clear the loan, then find the time period of the loan.

(9) Find the amount to be paid if Richard borrowed a sum of $5600 at 4% simple interest for 7 years.

(10) Nancy took a loan of $6300 at the rate of 9% simple interest per annum. If he paid an amount of $11970 to clear the loan, then find the time period of the loan.


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