Simple Interest
Math MCQs

Question :    What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 6% simple interest?

Correct Answer  $4148

Solution & Explanation

Solution

Given,

Principal (P) = $3050

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) = $3050 × 6% × 6

= $3050 ×⁶/₁₀₀ × 6

= ^{3050 × 6 × 6}/₁₀₀

= ^{18300 × 6}/₁₀₀

= ¹⁰⁹⁸⁰⁰/₁₀₀

= $1098

Thus, Simple Interest = $1098

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 = $3050 + $1098

= $4148

Thus, Amount to be paid = $4148 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 = $3050

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3050 + ($3050 × 6% × 6)

= $3050 + ($3050 ×⁶/₁₀₀ × 6)

= $3050 + (^{3050 × 6 × 6}/₁₀₀)

= $3050 + (^{18300 × 6}/₁₀₀)

= $3050 + (¹⁰⁹⁸⁰⁰/₁₀₀)

= $3050 + $1098 = $4148

Thus, Amount (A) to be paid = $4148 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 $3050, the simple interest in 1 year

= ⁶/₁₀₀ × 3050

= ^{6 × 3050}/₁₀₀

= ¹⁸³⁰⁰/₁₀₀ = $183

Thus, simple interest for 1 year = $183

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $183 × 6 = $1098

Thus, Simple Interest (SI) = $1098

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $1098

= $4148

Thus, Amount to be paid = $4148 Answer

Similar Questions

(1) Calculate the amount due if Joseph borrowed a sum of $3700 at 8% simple interest for 4 years.

(2) Elizabeth took a loan of $4900 at the rate of 10% simple interest per annum. If he paid an amount of $9310 to clear the loan, then find the time period of the loan.

(3) If Karen borrowed $3950 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(4) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 10% simple interest?

(5) What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 8% simple interest?

(6) What amount will be due after 2 years if William borrowed a sum of $3250 at a 4% simple interest?

(7) Calculate the amount due after 9 years if Joseph borrowed a sum of $5700 at a rate of 2% simple interest.

(8) Paul had to pay $5123 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(9) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $8000 to clear the loan, then find the time period of the loan.

(10) William took a loan of $5000 at the rate of 9% simple interest per annum. If he paid an amount of $9050 to clear the loan, then find the time period of the loan.