Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 6% simple interest.

Correct Answer  $8400

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 6%

Time (t) = 10 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) = $5250 × 6% × 10

= $5250 ×⁶/₁₀₀ × 10

= ^{5250 × 6 × 10}/₁₀₀

= ^{31500 × 10}/₁₀₀

= ³¹⁵⁰⁰⁰/₁₀₀

= $3150

Thus, Simple Interest = $3150

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 = $5250 + $3150

= $8400

Thus, Amount to be paid = $8400 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 = $5250

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5250 + ($5250 × 6% × 10)

= $5250 + ($5250 ×⁶/₁₀₀ × 10)

= $5250 + (^{5250 × 6 × 10}/₁₀₀)

= $5250 + (^{31500 × 10}/₁₀₀)

= $5250 + (³¹⁵⁰⁰⁰/₁₀₀)

= $5250 + $3150 = $8400

Thus, Amount (A) to be paid = $8400 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 $5250, the simple interest in 1 year

= ⁶/₁₀₀ × 5250

= ^{6 × 5250}/₁₀₀

= ³¹⁵⁰⁰/₁₀₀ = $315

Thus, simple interest for 1 year = $315

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $315 × 10 = $3150

Thus, Simple Interest (SI) = $3150

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $3150

= $8400

Thus, Amount to be paid = $8400 Answer

Similar Questions

(1) What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 5% simple interest?

(2) Calculate the amount due if William borrowed a sum of $3500 at 8% simple interest for 4 years.

(3) What amount does William have to pay after 6 years if he takes a loan of $3500 at 4% simple interest?

(4) What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 6% simple interest?

(5) David took a loan of $4800 at the rate of 6% simple interest per annum. If he paid an amount of $7680 to clear the loan, then find the time period of the loan.

(6) Sarah took a loan of $5700 at the rate of 6% simple interest per annum. If he paid an amount of $7752 to clear the loan, then find the time period of the loan.

(7) What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 3% simple interest?

(8) How much loan did Dorothy borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9062.5 to clear it?

(9) Find the amount to be paid if Thomas borrowed a sum of $5800 at 9% simple interest for 8 years.

(10) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $12127 to clear the loan, then find the time period of the loan.