Simple Interest
MCQs Math


Question:     Elizabeth took a loan of $4900 at the rate of 8% simple interest per annum. If he paid an amount of $7644 to clear the loan, then find the time period of the loan.


Correct Answer  7

Solution And Explanation

Solution

Given,

Principal (P) = $4900

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

Amount (A) = $7644

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 = $7644 – $4900 = $2744

Thus, Simple Interest = $2744

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 × 2744/4900 × 8

= 274400/39200

= 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) = $4900

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

Simple Interest = $2744 (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 $4900

= 8/100 × 4900

= 8 × 4900/100

= 39200/100 = 392

Thus, simple Interest for 1 year = $392

Now,

∵ If the simple Interest is $392, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/392 years

∴ If the simple Interest is $2744, then the time = 1/392 × 2744 years

= 1 × 2744/392 years

= 2744/392 = 7 years

Thus, time (T) = 7 years Answer


Similar Questions

(1) Calculate the amount due if Thomas borrowed a sum of $3800 at 10% simple interest for 4 years.

(2) How much loan did Ryan borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9875 to clear it?

(3) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 6% simple interest?

(4) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 10% simple interest?

(5) How much loan did Ashley borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7205 to clear it?

(6) In how much time a principal of $3000 will amount to $3180 at a simple interest of 2% per annum?

(7) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 4% simple interest?

(8) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 8% simple interest?

(9) Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 8% simple interest.

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


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