Simple Interest
MCQs Math


Question:     Find the amount to be paid if Karen borrowed a sum of $5950 at 10% simple interest for 7 years.


Correct Answer  $10115

Solution And Explanation

Solution

Given,

Principal (P) = $5950

Rate of Simple Interest (SI) = 10%

Time (t) = 7 years

Thus, Amount (A) = ?

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

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

= $5950 ×10/100 × 7

= 5950 × 10 × 7/100

= 59500 × 7/100

= 416500/100

= $4165

Thus, Simple Interest = $4165

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 + $4165

= $10115

Thus, Amount to be paid = $10115 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) = 10%

And, Time (t) = 7 years

Thus, Amount (A)

= $5950 + ($5950 × 10% × 7)

= $5950 + ($5950 ×10/100 × 7)

= $5950 + (5950 × 10 × 7/100)

= $5950 + (59500 × 7/100)

= $5950 + (416500/100)

= $5950 + $4165 = $10115

Thus, Amount (A) to be paid = $10115 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $5950, the simple interest in 1 year

= 10/100 × 5950

= 10 × 5950/100

= 59500/100 = $595

Thus, simple interest for 1 year = $595

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $595 × 7 = $4165

Thus, Simple Interest (SI) = $4165

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5950 + $4165

= $10115

Thus, Amount to be paid = $10115 Answer


Similar Questions

(1) Find the amount to be paid if Charles borrowed a sum of $5900 at 10% simple interest for 8 years.

(2) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 5% simple interest?

(3) David took a loan of $4800 at the rate of 8% simple interest per annum. If he paid an amount of $7104 to clear the loan, then find the time period of the loan.

(4) How much loan did Kenneth borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8400 to clear it?

(5) Daniel took a loan of $6200 at the rate of 10% simple interest per annum. If he paid an amount of $11780 to clear the loan, then find the time period of the loan.

(6) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 7% simple interest?

(7) Lisa took a loan of $6100 at the rate of 7% simple interest per annum. If he paid an amount of $10370 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due if Charles borrowed a sum of $3900 at 7% simple interest for 4 years.

(9) Calculate the amount due if Sarah borrowed a sum of $3850 at 9% simple interest for 3 years.

(10) John took a loan of $4400 at the rate of 10% simple interest per annum. If he paid an amount of $8360 to clear the loan, then find the time period of the loan.


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