Simple Interest
Math MCQs

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

Correct Answer  $7140

Solution & Explanation

Solution

Given,

Principal (P) = $5950

Rate of Simple Interest (SI) = 2%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $5950 × 2% × 10

= $5950 ײ/₁₀₀ × 10

= ^{5950 × 2 × 10}/₁₀₀

= ^{11900 × 10}/₁₀₀

= ¹¹⁹⁰⁰⁰/₁₀₀

= $1190

Thus, Simple Interest = $1190

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 = $5950 + $1190

= $7140

Thus, Amount to be paid = $7140 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 = $5950

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 10 years

Thus, Amount (A)

= $5950 + ($5950 × 2% × 10)

= $5950 + ($5950 ײ/₁₀₀ × 10)

= $5950 + (^{5950 × 2 × 10}/₁₀₀)

= $5950 + (^{11900 × 10}/₁₀₀)

= $5950 + (¹¹⁹⁰⁰⁰/₁₀₀)

= $5950 + $1190 = $7140

Thus, Amount (A) to be paid = $7140 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = ²/₁₀₀

∴ For $5950, the simple interest in 1 year

= ²/₁₀₀ × 5950

= ^{2 × 5950}/₁₀₀

= ¹¹⁹⁰⁰/₁₀₀ = $119

Thus, simple interest for 1 year = $119

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $119 × 10 = $1190

Thus, Simple Interest (SI) = $1190

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5950 + $1190

= $7140

Thus, Amount to be paid = $7140 Answer

Similar Questions

(1) Anthony took a loan of $6600 at the rate of 7% simple interest per annum. If he paid an amount of $11220 to clear the loan, then find the time period of the loan.

(2) Elizabeth took a loan of $4900 at the rate of 7% simple interest per annum. If he paid an amount of $8330 to clear the loan, then find the time period of the loan.

(3) How much loan did Richard borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6160 to clear it?

(4) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 3% simple interest.

(5) How much loan did Steven borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7920 to clear it?

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

(7) Daniel took a loan of $6200 at the rate of 8% simple interest per annum. If he paid an amount of $10664 to clear the loan, then find the time period of the loan.

(8) John took a loan of $4400 at the rate of 6% simple interest per annum. If he paid an amount of $6248 to clear the loan, then find the time period of the loan.

(9) Sandra took a loan of $6900 at the rate of 9% simple interest per annum. If he paid an amount of $13110 to clear the loan, then find the time period of the loan.

(10) Joseph took a loan of $5400 at the rate of 6% simple interest per annum. If he paid an amount of $7992 to clear the loan, then find the time period of the loan.