Simple Interest
Math MCQs

Question :  ( 1 of 10 )  Find the amount to be paid if Richard borrowed a sum of $5600 at 4% simple interest for 7 years.

Correct Answer  $7168

Solution & Explanation

Solution

Given,

Principal (P) = $5600

Rate of Simple Interest (SI) = 4%

Time (t) = 7 years

Thus, Amount (A) = ?

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

Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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) = $5600 × 4% × 7

= $5600 ×⁴/₁₀₀ × 7

= ^{5600 × 4 × 7}/₁₀₀

= ^{22400 × 7}/₁₀₀

= ¹⁵⁶⁸⁰⁰/₁₀₀

= $1568

Thus, Simple Interest = $1568

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 = $5600 + $1568

= $7168

Thus, Amount to be paid = $7168 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 = $5600

Rate of Simple Interest (SI) or (R) = 4%

And, Time (t) = 7 years

Thus, Amount (A)

= $5600 + ($5600 × 4% × 7)

= $5600 + ($5600 ×⁴/₁₀₀ × 7)

= $5600 + (^{5600 × 4 × 7}/₁₀₀)

= $5600 + (^{22400 × 7}/₁₀₀)

= $5600 + (¹⁵⁶⁸⁰⁰/₁₀₀)

= $5600 + $1568 = $7168

Thus, Amount (A) to be paid = $7168 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 4%

This, means, $4 per $100 per year

∵ For $100, the simple interest for 1 year = $4

∴ For $1, the simple interest for 1 year = ⁴/₁₀₀

∴ For $5600, the simple interest in 1 year

= ⁴/₁₀₀ × 5600

= ^{4 × 5600}/₁₀₀

= ²²⁴⁰⁰/₁₀₀ = $224

Thus, simple interest for 1 year = $224

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $224 × 7 = $1568

Thus, Simple Interest (SI) = $1568

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5600 + $1568

= $7168

Thus, Amount to be paid = $7168 Answer

Similar Questions

(1) Find the amount to be paid if Christopher borrowed a sum of $6000 at 4% simple interest for 7 years.

(2) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 5% simple interest?

(3) Barbara took a loan of $5100 at the rate of 10% simple interest per annum. If he paid an amount of $8160 to clear the loan, then find the time period of the loan.

(4) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 9% simple interest?

(5) If Lisa paid $4860 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(6) Calculate the amount due if Karen borrowed a sum of $3950 at 10% simple interest for 4 years.

(7) Emily had to pay $5320 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(8) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 4% simple interest?

(9) How much loan did Christopher borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6600 to clear it?

(10) In how much time a principal of $3100 will amount to $3348 at a simple interest of 2% per annum?