Simple Interest
MCQs Math


Question:     Susan took a loan of $5300 at the rate of 10% simple interest per annum. If he paid an amount of $10070 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $5300

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

Amount (A) = $10070

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 = $10070 – $5300 = $4770

Thus, Simple Interest = $4770

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 × 4770/5300 × 10

= 477000/53000

= 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) = $5300

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

Simple Interest = $4770 (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 $5300

= 10/100 × 5300

= 10 × 5300/100

= 53000/100 = 530

Thus, simple Interest for 1 year = $530

Now,

∵ If the simple Interest is $530, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/530 years

∴ If the simple Interest is $4770, then the time = 1/530 × 4770 years

= 1 × 4770/530 years

= 4770/530 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) Calculate the amount due if Barbara borrowed a sum of $3550 at 9% simple interest for 4 years.

(2) William had to pay $4025 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(3) Find the amount to be paid if William borrowed a sum of $5500 at 8% simple interest for 8 years.

(4) What amount will be due after 2 years if James borrowed a sum of $3000 at a 4% simple interest?

(5) Calculate the amount due if Thomas borrowed a sum of $3800 at 3% simple interest for 4 years.

(6) Sandra had to pay $4717 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(7) Find the amount to be paid if John borrowed a sum of $5200 at 5% simple interest for 8 years.

(8) What amount will be due after 2 years if Kenneth borrowed a sum of $4000 at a 10% simple interest?

(9) Find the amount to be paid if Patricia borrowed a sum of $5150 at 9% simple interest for 7 years.

(10) Find the amount to be paid if Robert borrowed a sum of $5100 at 8% simple interest for 7 years.


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