Simple Interest
Math MCQs

Question :  ( 1 of 10 )  What amount does John have to pay after 6 years if he takes a loan of $3200 at 6% simple interest?

Correct Answer  $4352

Solution & Explanation

Solution

Given,

Principal (P) = $3200

Rate of Simple Interest (SI) = 6%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $3200 × 6% × 6

= $3200 ×⁶/₁₀₀ × 6

= ^{3200 × 6 × 6}/₁₀₀

= ^{19200 × 6}/₁₀₀

= ¹¹⁵²⁰⁰/₁₀₀

= $1152

Thus, Simple Interest = $1152

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 = $3200 + $1152

= $4352

Thus, Amount to be paid = $4352 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 = $3200

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 6 years

Thus, Amount (A)

= $3200 + ($3200 × 6% × 6)

= $3200 + ($3200 ×⁶/₁₀₀ × 6)

= $3200 + (^{3200 × 6 × 6}/₁₀₀)

= $3200 + (^{19200 × 6}/₁₀₀)

= $3200 + (¹¹⁵²⁰⁰/₁₀₀)

= $3200 + $1152 = $4352

Thus, Amount (A) to be paid = $4352 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = ⁶/₁₀₀

∴ For $3200, the simple interest in 1 year

= ⁶/₁₀₀ × 3200

= ^{6 × 3200}/₁₀₀

= ¹⁹²⁰⁰/₁₀₀ = $192

Thus, simple interest for 1 year = $192

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $192 × 6 = $1152

Thus, Simple Interest (SI) = $1152

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3200 + $1152

= $4352

Thus, Amount to be paid = $4352 Answer

Similar Questions

(1) Calculate the amount due if Joseph borrowed a sum of $3700 at 2% simple interest for 3 years.

(2) Elizabeth took a loan of $4900 at the rate of 8% simple interest per annum. If he paid an amount of $8820 to clear the loan, then find the time period of the loan.

(3) Nancy took a loan of $6300 at the rate of 9% simple interest per annum. If he paid an amount of $10836 to clear the loan, then find the time period of the loan.

(4) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 6% simple interest?

(5) Susan took a loan of $5300 at the rate of 10% simple interest per annum. If he paid an amount of $9010 to clear the loan, then find the time period of the loan.

(6) Betty had to pay $4887.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(7) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 9% simple interest.

(8) Patricia took a loan of $4300 at the rate of 8% simple interest per annum. If he paid an amount of $7396 to clear the loan, then find the time period of the loan.

(9) Karen took a loan of $5900 at the rate of 9% simple interest per annum. If he paid an amount of $10148 to clear the loan, then find the time period of the loan.

(10) What amount will be due after 2 years if Mark borrowed a sum of $3700 at a 5% simple interest?