Simple Interest
Math MCQs

Question :    What amount does William have to pay after 6 years if he takes a loan of $3500 at 10% simple interest?

Correct Answer  $5600

Solution & Explanation

Solution

Given,

Principal (P) = $3500

Rate of Simple Interest (SI) = 10%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3500 × 10% × 6

= $3500 ×¹⁰/₁₀₀ × 6

= ^{3500 × 10 × 6}/₁₀₀

= ^{35000 × 6}/₁₀₀

= ²¹⁰⁰⁰⁰/₁₀₀

= $2100

Thus, Simple Interest = $2100

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 = $3500 + $2100

= $5600

Thus, Amount to be paid = $5600 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 = $3500

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 6 years

Thus, Amount (A)

= $3500 + ($3500 × 10% × 6)

= $3500 + ($3500 ×¹⁰/₁₀₀ × 6)

= $3500 + (^{3500 × 10 × 6}/₁₀₀)

= $3500 + (^{35000 × 6}/₁₀₀)

= $3500 + (²¹⁰⁰⁰⁰/₁₀₀)

= $3500 + $2100 = $5600

Thus, Amount (A) to be paid = $5600 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = ¹⁰/₁₀₀

∴ For $3500, the simple interest in 1 year

= ¹⁰/₁₀₀ × 3500

= ^{10 × 3500}/₁₀₀

= ³⁵⁰⁰⁰/₁₀₀ = $350

Thus, simple interest for 1 year = $350

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $350 × 6 = $2100

Thus, Simple Interest (SI) = $2100

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3500 + $2100

= $5600

Thus, Amount to be paid = $5600 Answer

Similar Questions

(1) What amount does William have to pay after 5 years if he takes a loan of $3500 at 2% simple interest?

(2) If Betty paid $4930 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(3) Margaret took a loan of $6700 at the rate of 10% simple interest per annum. If he paid an amount of $12060 to clear the loan, then find the time period of the loan.

(4) Susan took a loan of $5300 at the rate of 8% simple interest per annum. If he paid an amount of $9540 to clear the loan, then find the time period of the loan.

(5) Elizabeth had to pay $3760.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(6) Calculate the amount due if John borrowed a sum of $3200 at 6% simple interest for 3 years.

(7) Calculate the amount due if James borrowed a sum of $3000 at 10% simple interest for 3 years.

(8) Patricia took a loan of $4300 at the rate of 10% simple interest per annum. If he paid an amount of $8170 to clear the loan, then find the time period of the loan.

(9) Find the amount to be paid if Susan borrowed a sum of $5650 at 9% simple interest for 8 years.

(10) Margaret took a loan of $6700 at the rate of 7% simple interest per annum. If he paid an amount of $9514 to clear the loan, then find the time period of the loan.