Simple Interest
MCQs Math


Question:     Lisa took a loan of $6100 at the rate of 8% simple interest per annum. If he paid an amount of $9516 to clear the loan, then find the time period of the loan.


Correct Answer  7

Solution And Explanation

Solution

Given,

Principal (P) = $6100

Rate of Simple Interest (R) = 8% per annum

Amount (A) = $9516

Thus, time (T) = ?

Method (1) Using Formula

Calculation of Simple Interest, when Principal and Amount are given

Formual to Calculate Simple Interest when Principal and Amount are given

We know that, Amount (A) = Principal (P) + Simple Interest (SI)

⇒ Simple Interest (SI) = Amount – Principal

⇒ SI = $9516 – $6100 = $3416

Thus, Simple Interest = $3416

Calculation of the Time using forumula when Amount, Simple Interest and Principal are known

Formula to find the Time (T)

Time (T) = 100 × Simple Interest/Principal × Rate of Interest

⇒ T = 100 × SI/P × R

Thus, Time (T) = 100 × 3416/6100 × 8

= 341600/48800

= 7 years (using formula)

Thus, Time (T) = 7 years (from time taken before calculation)Answer

Calculation of the Time using Unitary Method when Amount, Simple Interest and Principal are known

Here, we have

Principal (P) = $6100

Rate of Simple Interest (R) = 8% per annum

Simple Interest = $3416 (As calculated above by subtracting Principal from the Amount given)

We know that, interest is calculated on the basis of the Principal.

This means Simple Interest for 1 year = Rate of simple interest × Principal

Thus, Simple Interest for 1 year = 8% of Principal

= 8% of $6100

= 8/100 × 6100

= 8 × 6100/100

= 48800/100 = 488

Thus, simple Interest for 1 year = $488

Now,

∵ If the simple Interest is $488, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/488 years

∴ If the simple Interest is $3416, then the time = 1/488 × 3416 years

= 1 × 3416/488 years

= 3416/488 = 7 years

Thus, time (T) = 7 years Answer


Similar Questions

(1) Find the amount to be paid if Jessica borrowed a sum of $5750 at 3% simple interest for 8 years.

(2) Calculate the amount due if Linda borrowed a sum of $3350 at 8% simple interest for 4 years.

(3) Find the amount to be paid if Charles borrowed a sum of $5900 at 2% simple interest for 7 years.

(4) Find the amount to be paid if David borrowed a sum of $5400 at 4% simple interest for 7 years.

(5) Jennifer had to pay $3640 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(6) Calculate the amount due if Charles borrowed a sum of $3900 at 7% simple interest for 3 years.

(7) Calculate the amount due if Sarah borrowed a sum of $3850 at 4% simple interest for 3 years.

(8) Calculate the amount due after 9 years if Richard borrowed a sum of $5600 at a rate of 10% simple interest.

(9) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 10% simple interest?

(10) If Anthony paid $5160 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.


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