Simple Interest
MCQs Math


Question:     James took a loan of $4000 at the rate of 10% simple interest per annum. If he paid an amount of $7600 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $4000

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

Amount (A) = $7600

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 = $7600 – $4000 = $3600

Thus, Simple Interest = $3600

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 × 3600/4000 × 10

= 360000/40000

= 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) = $4000

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

Simple Interest = $3600 (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 $4000

= 10/100 × 4000

= 10 × 4000/100

= 40000/100 = 400

Thus, simple Interest for 1 year = $400

Now,

∵ If the simple Interest is $400, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/400 years

∴ If the simple Interest is $3600, then the time = 1/400 × 3600 years

= 1 × 3600/400 years

= 3600/400 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) In how much time a principal of $3050 will amount to $3324.5 at a simple interest of 3% per annum?

(2) If Charles paid $4524 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(3) Calculate the amount due if Karen borrowed a sum of $3950 at 5% simple interest for 3 years.

(4) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 7% simple interest?

(5) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 6% simple interest.

(6) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 5% simple interest?

(7) What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 5% simple interest?

(8) Calculate the amount due if Robert borrowed a sum of $3100 at 9% simple interest for 4 years.

(9) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $8740 to clear the loan, then find the time period of the loan.

(10) Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $6314 to clear the loan, then find the time period of the loan.


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