Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Joseph borrowed a sum of $5700 at a rate of 6% simple interest.

Correct Answer  $9120

Solution & Explanation

Solution

Given,

Principal (P) = $5700

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) = $5700 × 6% × 10

= $5700 ×⁶/₁₀₀ × 10

= ^{5700 × 6 × 10}/₁₀₀

= ^{34200 × 10}/₁₀₀

= ³⁴²⁰⁰⁰/₁₀₀

= $3420

Thus, Simple Interest = $3420

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 = $5700 + $3420

= $9120

Thus, Amount to be paid = $9120 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 = $5700

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5700 + ($5700 × 6% × 10)

= $5700 + ($5700 ×⁶/₁₀₀ × 10)

= $5700 + (^{5700 × 6 × 10}/₁₀₀)

= $5700 + (^{34200 × 10}/₁₀₀)

= $5700 + (³⁴²⁰⁰⁰/₁₀₀)

= $5700 + $3420 = $9120

Thus, Amount (A) to be paid = $9120 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 $5700, the simple interest in 1 year

= ⁶/₁₀₀ × 5700

= ^{6 × 5700}/₁₀₀

= ³⁴²⁰⁰/₁₀₀ = $342

Thus, simple interest for 1 year = $342

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $342 × 10 = $3420

Thus, Simple Interest (SI) = $3420

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5700 + $3420

= $9120

Thus, Amount to be paid = $9120 Answer

Similar Questions

(1) How much loan did Kenneth borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8050 to clear it?

(2) Find the amount to be paid if James borrowed a sum of $5000 at 4% simple interest for 7 years.

(3) Find the amount to be paid if John borrowed a sum of $5200 at 2% simple interest for 8 years.

(4) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 6% simple interest.

(5) Calculate the amount due if Jennifer borrowed a sum of $3250 at 8% simple interest for 3 years.

(6) Calculate the amount due if William borrowed a sum of $3500 at 2% simple interest for 3 years.

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

(8) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 9% simple interest?

(9) How much loan did Linda borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $5885 to clear it?

(10) Find the amount to be paid if James borrowed a sum of $5000 at 7% simple interest for 7 years.