Simple Interest
MCQs Math


Question:     Patricia took a loan of $4300 at the rate of 10% simple interest per annum. If he paid an amount of $7740 to clear the loan, then find the time period of the loan.


Correct Answer  8

Solution And Explanation

Solution

Given,

Principal (P) = $4300

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

Amount (A) = $7740

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 = $7740 – $4300 = $3440

Thus, Simple Interest = $3440

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 × 3440/4300 × 10

= 344000/43000

= 8 years (using formula)

Thus, Time (T) = 8 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) = $4300

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

Simple Interest = $3440 (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 $4300

= 10/100 × 4300

= 10 × 4300/100

= 43000/100 = 430

Thus, simple Interest for 1 year = $430

Now,

∵ If the simple Interest is $430, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/430 years

∴ If the simple Interest is $3440, then the time = 1/430 × 3440 years

= 1 × 3440/430 years

= 3440/430 = 8 years

Thus, time (T) = 8 years Answer


Similar Questions

(1) If Emily paid $5510 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(2) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 7% simple interest?

(3) What amount will be due after 2 years if John borrowed a sum of $3100 at a 9% simple interest?

(4) What amount will be due after 2 years if Paul borrowed a sum of $3850 at a 9% simple interest?

(5) What amount will be due after 2 years if William borrowed a sum of $3250 at a 7% simple interest?

(6) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 8% simple interest.

(7) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 8% simple interest?

(8) Jessica had to pay $4312.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(9) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 3% simple interest?

(10) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 9% simple interest.


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