Simple Interest
MCQs Math


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


Correct Answer  $8362

Solution And Explanation

Solution

Given,

Principal (P) = $5650

Rate of Simple Interest (SI) = 6%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $5650 × 6% × 8

= $5650 ×6/100 × 8

= 5650 × 6 × 8/100

= 33900 × 8/100

= 271200/100

= $2712

Thus, Simple Interest = $2712

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 = $5650 + $2712

= $8362

Thus, Amount to be paid = $8362 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 = $5650

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 8 years

Thus, Amount (A)

= $5650 + ($5650 × 6% × 8)

= $5650 + ($5650 ×6/100 × 8)

= $5650 + (5650 × 6 × 8/100)

= $5650 + (33900 × 8/100)

= $5650 + (271200/100)

= $5650 + $2712 = $8362

Thus, Amount (A) to be paid = $8362 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $5650, the simple interest in 1 year

= 6/100 × 5650

= 6 × 5650/100

= 33900/100 = $339

Thus, simple interest for 1 year = $339

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $339 × 8 = $2712

Thus, Simple Interest (SI) = $2712

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5650 + $2712

= $8362

Thus, Amount to be paid = $8362 Answer


Similar Questions

(1) If Barbara borrowed $3550 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(2) Calculate the amount due if David borrowed a sum of $3400 at 8% simple interest for 3 years.

(3) How much loan did Andrew borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7820 to clear it?

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

(5) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $9500 to clear the loan, then find the time period of the loan.

(6) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 4% simple interest?

(7) Lisa took a loan of $6100 at the rate of 10% simple interest per annum. If he paid an amount of $10980 to clear the loan, then find the time period of the loan.

(8) If William paid $3920 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(9) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 7% simple interest?

(10) John took a loan of $4400 at the rate of 8% simple interest per annum. If he paid an amount of $6512 to clear the loan, then find the time period of the loan.


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