Simple Interest
Math MCQs

Question :    What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 9% simple interest?

Correct Answer  $5852

Solution & Explanation

Solution

Given,

Principal (P) = $3800

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) = $3800 × 9% × 6

= $3800 ×⁹/₁₀₀ × 6

= ^{3800 × 9 × 6}/₁₀₀

= ^{34200 × 6}/₁₀₀

= ²⁰⁵²⁰⁰/₁₀₀

= $2052

Thus, Simple Interest = $2052

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 = $3800 + $2052

= $5852

Thus, Amount to be paid = $5852 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 = $3800

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3800 + ($3800 × 9% × 6)

= $3800 + ($3800 ×⁹/₁₀₀ × 6)

= $3800 + (^{3800 × 9 × 6}/₁₀₀)

= $3800 + (^{34200 × 6}/₁₀₀)

= $3800 + (²⁰⁵²⁰⁰/₁₀₀)

= $3800 + $2052 = $5852

Thus, Amount (A) to be paid = $5852 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 $3800, the simple interest in 1 year

= ⁹/₁₀₀ × 3800

= ^{9 × 3800}/₁₀₀

= ³⁴²⁰⁰/₁₀₀ = $342

Thus, simple interest for 1 year = $342

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $342 × 6 = $2052

Thus, Simple Interest (SI) = $2052

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3800 + $2052

= $5852

Thus, Amount to be paid = $5852 Answer

Similar Questions

(1) How much loan did Paul borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8375 to clear it?

(2) Nancy took a loan of $6300 at the rate of 10% simple interest per annum. If he paid an amount of $10080 to clear the loan, then find the time period of the loan.

(3) How much loan did Cynthia borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9540 to clear it?

(4) Find the amount to be paid if William borrowed a sum of $5500 at 4% simple interest for 7 years.

(5) What amount does James have to pay after 6 years if he takes a loan of $3000 at 6% simple interest?

(6) Calculate the amount due if Linda borrowed a sum of $3350 at 5% simple interest for 3 years.

(7) Charles took a loan of $5800 at the rate of 8% simple interest per annum. If he paid an amount of $9976 to clear the loan, then find the time period of the loan.

(8) Mark took a loan of $6800 at the rate of 8% simple interest per annum. If he paid an amount of $11152 to clear the loan, then find the time period of the loan.

(9) What amount does Christopher have to pay after 5 years if he takes a loan of $4000 at 3% simple interest?

(10) If Linda paid $3752 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.