Simple Interest
MCQs Math


Question:     Daniel took a loan of $6200 at the rate of 10% simple interest per annum. If he paid an amount of $11780 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $6200

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

Amount (A) = $11780

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 = $11780 – $6200 = $5580

Thus, Simple Interest = $5580

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 × 5580/6200 × 10

= 558000/62000

= 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) = $6200

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

Simple Interest = $5580 (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 $6200

= 10/100 × 6200

= 10 × 6200/100

= 62000/100 = 620

Thus, simple Interest for 1 year = $620

Now,

∵ If the simple Interest is $620, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/620 years

∴ If the simple Interest is $5580, then the time = 1/620 × 5580 years

= 1 × 5580/620 years

= 5580/620 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) Sarah had to pay $4196.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(2) Jennifer took a loan of $4500 at the rate of 8% simple interest per annum. If he paid an amount of $7740 to clear the loan, then find the time period of the loan.

(3) Susan took a loan of $5300 at the rate of 9% simple interest per annum. If he paid an amount of $10070 to clear the loan, then find the time period of the loan.

(4) Find the amount to be paid if Sarah borrowed a sum of $5850 at 2% simple interest for 8 years.

(5) William took a loan of $5000 at the rate of 8% simple interest per annum. If he paid an amount of $7800 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due if Charles borrowed a sum of $3900 at 9% simple interest for 4 years.

(7) Find the amount to be paid if Thomas borrowed a sum of $5800 at 2% simple interest for 8 years.

(8) Calculate the amount due if Christopher borrowed a sum of $4000 at 9% simple interest for 3 years.

(9) In how much time a principal of $3000 will amount to $3240 at a simple interest of 2% per annum?

(10) What amount will be due after 2 years if Steven borrowed a sum of $3800 at a 5% simple interest?


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