Simple Interest
MCQs Math


Question:     Margaret took a loan of $6700 at the rate of 10% simple interest per annum. If he paid an amount of $10720 to clear the loan, then find the time period of the loan.


Correct Answer  6

Solution And Explanation

Solution

Given,

Principal (P) = $6700

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

Amount (A) = $10720

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 = $10720 – $6700 = $4020

Thus, Simple Interest = $4020

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 × 4020/6700 × 10

= 402000/67000

= 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) = $6700

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

Simple Interest = $4020 (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 $6700

= 10/100 × 6700

= 10 × 6700/100

= 67000/100 = 670

Thus, simple Interest for 1 year = $670

Now,

∵ If the simple Interest is $670, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/670 years

∴ If the simple Interest is $4020, then the time = 1/670 × 4020 years

= 1 × 4020/670 years

= 4020/670 = 6 years

Thus, time (T) = 6 years Answer


Similar Questions

(1) Find the amount to be paid if Richard borrowed a sum of $5600 at 2% simple interest for 8 years.

(2) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 8% simple interest.

(3) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 10% simple interest?

(4) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 2% simple interest?

(5) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 6% simple interest?

(6) James took a loan of $4000 at the rate of 10% simple interest per annum. If he paid an amount of $6400 to clear the loan, then find the time period of the loan.

(7) Mary took a loan of $4100 at the rate of 10% simple interest per annum. If he paid an amount of $7380 to clear the loan, then find the time period of the loan.

(8) Find the amount to be paid if Linda borrowed a sum of $5350 at 4% simple interest for 7 years.

(9) Linda took a loan of $4700 at the rate of 9% simple interest per annum. If he paid an amount of $7661 to clear the loan, then find the time period of the loan.

(10) Find the amount to be paid if Christopher borrowed a sum of $6000 at 6% simple interest for 8 years.


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