Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 7% simple interest.

Correct Answer  $9095

Solution & Explanation

Solution

Given,

Principal (P) = $5350

Rate of Simple Interest (SI) = 7%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 7% simple interest means, Rate of Simple Interest (SI) is 7% 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) = $5350 × 7% × 10

= $5350 ×⁷/₁₀₀ × 10

= ^{5350 × 7 × 10}/₁₀₀

= ^{37450 × 10}/₁₀₀

= ³⁷⁴⁵⁰⁰/₁₀₀

= $3745

Thus, Simple Interest = $3745

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 = $5350 + $3745

= $9095

Thus, Amount to be paid = $9095 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 = $5350

Rate of Simple Interest (SI) or (R) = 7%

And, Time (t) = 10 years

Thus, Amount (A)

= $5350 + ($5350 × 7% × 10)

= $5350 + ($5350 ×⁷/₁₀₀ × 10)

= $5350 + (^{5350 × 7 × 10}/₁₀₀)

= $5350 + (^{37450 × 10}/₁₀₀)

= $5350 + (³⁷⁴⁵⁰⁰/₁₀₀)

= $5350 + $3745 = $9095

Thus, Amount (A) to be paid = $9095 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 7%

This, means, $7 per $100 per year

∵ For $100, the simple interest for 1 year = $7

∴ For $1, the simple interest for 1 year = ⁷/₁₀₀

∴ For $5350, the simple interest in 1 year

= ⁷/₁₀₀ × 5350

= ^{7 × 5350}/₁₀₀

= ³⁷⁴⁵⁰/₁₀₀ = $374.5

Thus, simple interest for 1 year = $374.5

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $374.5 × 10 = $3745

Thus, Simple Interest (SI) = $3745

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5350 + $3745

= $9095

Thus, Amount to be paid = $9095 Answer

Similar Questions

(1) Calculate the amount due after 10 years if Karen borrowed a sum of $5950 at a rate of 2% simple interest.

(2) How much loan did William borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $6875 to clear it?

(3) Richard took a loan of $5200 at the rate of 8% simple interest per annum. If he paid an amount of $8112 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due if James borrowed a sum of $3000 at 5% simple interest for 4 years.

(5) How much loan did Rebecca borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9180 to clear it?

(6) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 2% simple interest?

(7) Emily had to pay $5035 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

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

(9) Donald took a loan of $7000 at the rate of 6% simple interest per annum. If he paid an amount of $9940 to clear the loan, then find the time period of the loan.

(10) Elizabeth took a loan of $4900 at the rate of 8% simple interest per annum. If he paid an amount of $7644 to clear the loan, then find the time period of the loan.