Simple Interest
MCQs Math


Question:     Lisa took a loan of $6100 at the rate of 9% simple interest per annum. If he paid an amount of $11590 to clear the loan, then find the time period of the loan.


Correct Answer  10

Solution And Explanation

Solution

Given,

Principal (P) = $6100

Rate of Simple Interest (R) = 9% per annum

Amount (A) = $11590

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 = $11590 – $6100 = $5490

Thus, Simple Interest = $5490

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 × 5490/6100 × 9

= 549000/54900

= 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) = $6100

Rate of Simple Interest (R) = 9% per annum

Simple Interest = $5490 (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 = 9% of Principal

= 9% of $6100

= 9/100 × 6100

= 9 × 6100/100

= 54900/100 = 549

Thus, simple Interest for 1 year = $549

Now,

∵ If the simple Interest is $549, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/549 years

∴ If the simple Interest is $5490, then the time = 1/549 × 5490 years

= 1 × 5490/549 years

= 5490/549 = 10 years

Thus, time (T) = 10 years Answer


Similar Questions

(1) What amount will be due after 2 years if David borrowed a sum of $3200 at a 9% simple interest?

(2) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 3% simple interest?

(3) What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 6% simple interest?

(4) Anthony had to pay $4687 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(5) Find the amount to be paid if William borrowed a sum of $5500 at 5% simple interest for 7 years.

(6) Karen took a loan of $5900 at the rate of 10% simple interest per annum. If he paid an amount of $10620 to clear the loan, then find the time period of the loan.

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

(8) Find the amount to be paid if Robert borrowed a sum of $5100 at 3% simple interest for 8 years.

(9) Calculate the amount due if Jessica borrowed a sum of $3750 at 3% simple interest for 4 years.

(10) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 9% simple interest?


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