Simple Interest
MCQs Math


Question:     What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 10% simple interest?


Correct Answer  $6160

Solution And Explanation

Solution

Given,

Principal (P) = $3850

Rate of Simple Interest (SI) = 10%

Time (t) = 6 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) = $3850 × 10% × 6

= $3850 ×10/100 × 6

= 3850 × 10 × 6/100

= 38500 × 6/100

= 231000/100

= $2310

Thus, Simple Interest = $2310

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 = $3850 + $2310

= $6160

Thus, Amount to be paid = $6160 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 = $3850

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 6 years

Thus, Amount (A)

= $3850 + ($3850 × 10% × 6)

= $3850 + ($3850 ×10/100 × 6)

= $3850 + (3850 × 10 × 6/100)

= $3850 + (38500 × 6/100)

= $3850 + (231000/100)

= $3850 + $2310 = $6160

Thus, Amount (A) to be paid = $6160 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 $3850, the simple interest in 1 year

= 10/100 × 3850

= 10 × 3850/100

= 38500/100 = $385

Thus, simple interest for 1 year = $385

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $385 × 6 = $2310

Thus, Simple Interest (SI) = $2310

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3850 + $2310

= $6160

Thus, Amount to be paid = $6160 Answer


Similar Questions

(1) Patricia took a loan of $4300 at the rate of 7% simple interest per annum. If he paid an amount of $6407 to clear the loan, then find the time period of the loan.

(2) Find the amount to be paid if Karen borrowed a sum of $5950 at 3% simple interest for 7 years.

(3) What amount does William have to pay after 5 years if he takes a loan of $3500 at 7% simple interest?

(4) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 9% simple interest?

(5) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 6% simple interest.

(6) Nancy took a loan of $6300 at the rate of 6% simple interest per annum. If he paid an amount of $10080 to clear the loan, then find the time period of the loan.

(7) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 4% simple interest?

(8) John took a loan of $4400 at the rate of 6% simple interest per annum. If he paid an amount of $5984 to clear the loan, then find the time period of the loan.

(9) Find the amount to be paid if Karen borrowed a sum of $5950 at 4% simple interest for 8 years.

(10) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 7% simple interest?


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