Simple Interest
MCQs Math


Question:     Elizabeth took a loan of $4900 at the rate of 9% simple interest per annum. If he paid an amount of $8869 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $4900

Rate of Simple Interest (R) = 9% per annum

Amount (A) = $8869

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 = $8869 – $4900 = $3969

Thus, Simple Interest = $3969

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 × 3969/4900 × 9

= 396900/44100

= 9 years (using formula)

Thus, Time (T) = 9 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) = $4900

Rate of Simple Interest (R) = 9% per annum

Simple Interest = $3969 (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 = 9% of Principal

= 9% of $4900

= 9/100 × 4900

= 9 × 4900/100

= 44100/100 = 441

Thus, simple Interest for 1 year = $441

Now,

∵ If the simple Interest is $441, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/441 years

∴ If the simple Interest is $3969, then the time = 1/441 × 3969 years

= 1 × 3969/441 years

= 3969/441 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) If Robert paid $3348 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(2) Calculate the amount due if Sarah borrowed a sum of $3850 at 6% simple interest for 3 years.

(3) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 2% simple interest?

(4) Find the amount to be paid if Barbara borrowed a sum of $5550 at 10% simple interest for 8 years.

(5) Find the amount to be paid if Patricia borrowed a sum of $5150 at 3% simple interest for 7 years.

(6) Calculate the amount due if Richard borrowed a sum of $3600 at 3% simple interest for 3 years.

(7) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 8% simple interest?

(8) What amount does William have to pay after 6 years if he takes a loan of $3500 at 6% simple interest?

(9) Calculate the amount due if William borrowed a sum of $3500 at 4% simple interest for 3 years.

(10) Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $10764 to clear the loan, then find the time period of the loan.


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