Simple Interest
Math MCQs

Question :    Find the amount to be paid if Linda borrowed a sum of $5350 at 5% simple interest for 8 years.

Correct Answer  $7490

Solution & Explanation

Solution

Given,

Principal (P) = $5350

Rate of Simple Interest (SI) = 5%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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 × 5% × 8

= $5350 ×⁵/₁₀₀ × 8

= ^{5350 × 5 × 8}/₁₀₀

= ^{26750 × 8}/₁₀₀

= ²¹⁴⁰⁰⁰/₁₀₀

= $2140

Thus, Simple Interest = $2140

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 + $2140

= $7490

Thus, Amount to be paid = $7490 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) = 5%

And, Time (t) = 8 years

Thus, Amount (A)

= $5350 + ($5350 × 5% × 8)

= $5350 + ($5350 ×⁵/₁₀₀ × 8)

= $5350 + (^{5350 × 5 × 8}/₁₀₀)

= $5350 + (^{26750 × 8}/₁₀₀)

= $5350 + (²¹⁴⁰⁰⁰/₁₀₀)

= $5350 + $2140 = $7490

Thus, Amount (A) to be paid = $7490 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = ⁵/₁₀₀

∴ For $5350, the simple interest in 1 year

= ⁵/₁₀₀ × 5350

= ^{5 × 5350}/₁₀₀

= ²⁶⁷⁵⁰/₁₀₀ = $267.5

Thus, simple interest for 1 year = $267.5

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $267.5 × 8 = $2140

Thus, Simple Interest (SI) = $2140

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5350 + $2140

= $7490

Thus, Amount to be paid = $7490 Answer

Similar Questions

(1) What amount does Christopher have to pay after 6 years if he takes a loan of $4000 at 6% simple interest?

(2) Jennifer took a loan of $4500 at the rate of 8% simple interest per annum. If he paid an amount of $6660 to clear the loan, then find the time period of the loan.

(3) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 2% simple interest?

(4) In how much time a principal of $3150 will amount to $3528 at a simple interest of 3% per annum?

(5) James took a loan of $4000 at the rate of 8% simple interest per annum. If he paid an amount of $6240 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due after 9 years if James borrowed a sum of $5000 at a rate of 9% simple interest.

(7) How much loan did Thomas borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7250 to clear it?

(8) Find the amount to be paid if Jessica borrowed a sum of $5750 at 5% simple interest for 8 years.

(9) Daniel took a loan of $6200 at the rate of 8% simple interest per annum. If he paid an amount of $9672 to clear the loan, then find the time period of the loan.

(10) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 8% simple interest?