Simple Interest
MCQs Math


Question:     Elizabeth took a loan of $4900 at the rate of 10% simple interest per annum. If he paid an amount of $9310 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) = 10% per annum

Amount (A) = $9310

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 = $9310 – $4900 = $4410

Thus, Simple Interest = $4410

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 × 4410/4900 × 10

= 441000/49000

= 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) = 10% per annum

Simple Interest = $4410 (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 = 10% of Principal

= 10% of $4900

= 10/100 × 4900

= 10 × 4900/100

= 49000/100 = 490

Thus, simple Interest for 1 year = $490

Now,

∵ If the simple Interest is $490, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/490 years

∴ If the simple Interest is $4410, then the time = 1/490 × 4410 years

= 1 × 4410/490 years

= 4410/490 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) If Jennifer borrowed $3250 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(2) Find the amount to be paid if Mary borrowed a sum of $5050 at 5% simple interest for 8 years.

(3) Calculate the amount due if John borrowed a sum of $3200 at 4% simple interest for 3 years.

(4) In how much time a principal of $3150 will amount to $3433.5 at a simple interest of 3% per annum?

(5) If Elizabeth paid $4002 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(6) Richard took a loan of $5200 at the rate of 6% simple interest per annum. If he paid an amount of $8008 to clear the loan, then find the time period of the loan.

(7) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 2% simple interest?

(8) If Elizabeth paid $3864 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 Susan have to pay after 6 years if he takes a loan of $3650 at 5% simple interest?

(10) What amount does David have to pay after 6 years if he takes a loan of $3400 at 10% simple interest?


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