Simple Interest
Math MCQs

Question :  ( 1 of 10 )  What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 9% simple interest?

Correct Answer  $5005

Solution & Explanation

Solution

Given,

Principal (P) = $3250

Rate of Simple Interest (SI) = 9%

Time (t) = 6 years

Thus, Amount (A) = ?

The Rate of Interest is always calculated per annum, i.e. per year.

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% per annum.

Method (1) Using Formula

Calculation of Simple Interest

Formula to Calculate Simple Interest

Simple Interest (SI) = Principal × Rate × Time

Thus, Simple Interest (SI) = $3250 × 9% × 6

= $3250 ×⁹/₁₀₀ × 6

= ^{3250 × 9 × 6}/₁₀₀

= ^{29250 × 6}/₁₀₀

= ¹⁷⁵⁵⁰⁰/₁₀₀

= $1755

Thus, Simple Interest = $1755

Calculation of Amount

The total money paid to the lender by a borrower is called the Amount.

In other words, sum of priciple and interest is called the Amount.

Formula to Calculate the Amount

Amount = Principal + Interest

Thus, Amount = $3250 + $1755

= $5005

Thus, Amount to be paid = $5005 Answer

Method (2)

Calculation of Amount when Principal, Rate of Simple Interest and Time are given

Calculation of Amount directly using Principal, SI, and Time

Formula to calculate the Amount

Amount (A) = Principal (P) + Principal(P) × Rate of Interest (SI) × Time (t)

⇒ A = P + PRT

Here in the question, P = $3250

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 6 years

Thus, Amount (A)

= $3250 + ($3250 × 9% × 6)

= $3250 + ($3250 ×⁹/₁₀₀ × 6)

= $3250 + (^{3250 × 9 × 6}/₁₀₀)

= $3250 + (^{29250 × 6}/₁₀₀)

= $3250 + (¹⁷⁵⁵⁰⁰/₁₀₀)

= $3250 + $1755 = $5005

Thus, Amount (A) to be paid = $5005 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = ⁹/₁₀₀

∴ For $3250, the simple interest in 1 year

= ⁹/₁₀₀ × 3250

= ^{9 × 3250}/₁₀₀

= ²⁹²⁵⁰/₁₀₀ = $292.5

Thus, simple interest for 1 year = $292.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $292.5 × 6 = $1755

Thus, Simple Interest (SI) = $1755

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3250 + $1755

= $5005

Thus, Amount to be paid = $5005 Answer

Similar Questions

(1) Christopher had to pay $4480 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(2) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $6970 to clear the loan, then find the time period of the loan.

(3) Mark had to pay $4928 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(4) Christopher took a loan of $6000 at the rate of 8% simple interest per annum. If he paid an amount of $9360 to clear the loan, then find the time period of the loan.

(5) Mark took a loan of $6800 at the rate of 10% simple interest per annum. If he paid an amount of $10880 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due if Mary borrowed a sum of $3050 at 7% simple interest for 3 years.

(7) James took a loan of $4000 at the rate of 8% simple interest per annum. If he paid an amount of $6880 to clear the loan, then find the time period of the loan.

(8) James had to pay $3450 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(9) If Joshua paid $5488 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(10) William took a loan of $5000 at the rate of 9% simple interest per annum. If he paid an amount of $9500 to clear the loan, then find the time period of the loan.