Simple Interest
MCQs Math


Question:     Margaret took a loan of $6700 at the rate of 7% simple interest per annum. If he paid an amount of $10921 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $6700

Rate of Simple Interest (R) = 7% per annum

Amount (A) = $10921

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 = $10921 – $6700 = $4221

Thus, Simple Interest = $4221

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 × 4221/6700 × 7

= 422100/46900

= 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) = $6700

Rate of Simple Interest (R) = 7% per annum

Simple Interest = $4221 (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 = 7% of Principal

= 7% of $6700

= 7/100 × 6700

= 7 × 6700/100

= 46900/100 = 469

Thus, simple Interest for 1 year = $469

Now,

∵ If the simple Interest is $469, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/469 years

∴ If the simple Interest is $4221, then the time = 1/469 × 4221 years

= 1 × 4221/469 years

= 4221/469 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 3% simple interest?

(2) If Joseph paid $4440 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(3) Jennifer took a loan of $4500 at the rate of 9% simple interest per annum. If he paid an amount of $8145 to clear the loan, then find the time period of the loan.

(4) How much loan did Lisa borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7260 to clear it?

(5) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 7% simple interest.

(6) What amount will be due after 2 years if Mark borrowed a sum of $3700 at a 6% simple interest?

(7) Find the amount to be paid if James borrowed a sum of $5000 at 10% simple interest for 8 years.

(8) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 10% simple interest?

(9) Calculate the amount due if Linda borrowed a sum of $3350 at 10% simple interest for 3 years.

(10) Calculate the amount due if James borrowed a sum of $3000 at 7% simple interest for 4 years.


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