Simple Interest
MCQs Math


Question:     Mark took a loan of $6800 at the rate of 10% simple interest per annum. If he paid an amount of $13600 to clear the loan, then find the time period of the loan.


Correct Answer  10

Solution And Explanation

Solution

Given,

Principal (P) = $6800

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

Amount (A) = $13600

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 = $13600 – $6800 = $6800

Thus, Simple Interest = $6800

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 × 6800/6800 × 10

= 680000/68000

= 10 years (using formula)

Thus, Time (T) = 10 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) = $6800

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

Simple Interest = $6800 (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 $6800

= 10/100 × 6800

= 10 × 6800/100

= 68000/100 = 680

Thus, simple Interest for 1 year = $680

Now,

∵ If the simple Interest is $680, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/680 years

∴ If the simple Interest is $6800, then the time = 1/680 × 6800 years

= 1 × 6800/680 years

= 6800/680 = 10 years

Thus, time (T) = 10 years Answer


Similar Questions

(1) Find the amount to be paid if Jessica borrowed a sum of $5750 at 3% simple interest for 7 years.

(2) Linda took a loan of $4700 at the rate of 7% simple interest per annum. If he paid an amount of $7332 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 7% simple interest.

(4) Find the amount to be paid if Michael borrowed a sum of $5300 at 4% simple interest for 7 years.

(5) Find the amount to be paid if Barbara borrowed a sum of $5550 at 9% simple interest for 7 years.

(6) David took a loan of $4800 at the rate of 10% simple interest per annum. If he paid an amount of $9600 to clear the loan, then find the time period of the loan.

(7) Susan took a loan of $5300 at the rate of 8% simple interest per annum. If he paid an amount of $9116 to clear the loan, then find the time period of the loan.

(8) Find the amount to be paid if Michael borrowed a sum of $5300 at 9% simple interest for 7 years.

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

(10) How much loan did Laura borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9812.5 to clear it?


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