Simple Interest
MCQs Math


Question:     Barbara took a loan of $5100 at the rate of 8% simple interest per annum. If he paid an amount of $8364 to clear the loan, then find the time period of the loan.


Correct Answer  8

Solution And Explanation

Solution

Given,

Principal (P) = $5100

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

Amount (A) = $8364

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 = $8364 – $5100 = $3264

Thus, Simple Interest = $3264

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 × 3264/5100 × 8

= 326400/40800

= 8 years (using formula)

Thus, Time (T) = 8 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) = $5100

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

Simple Interest = $3264 (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 $5100

= 8/100 × 5100

= 8 × 5100/100

= 40800/100 = 408

Thus, simple Interest for 1 year = $408

Now,

∵ If the simple Interest is $408, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/408 years

∴ If the simple Interest is $3264, then the time = 1/408 × 3264 years

= 1 × 3264/408 years

= 3264/408 = 8 years

Thus, time (T) = 8 years Answer


Similar Questions

(1) Lisa took a loan of $6100 at the rate of 10% simple interest per annum. If he paid an amount of $11590 to clear the loan, then find the time period of the loan.

(2) In how much time a principal of $3150 will amount to $3780 at a simple interest of 5% per annum?

(3) Find the amount to be paid if Mary borrowed a sum of $5050 at 3% simple interest for 8 years.

(4) Charles took a loan of $5800 at the rate of 8% simple interest per annum. If he paid an amount of $9048 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due if Christopher borrowed a sum of $4000 at 2% simple interest for 3 years.

(6) What amount does Michael have to pay after 5 years if he takes a loan of $3300 at 8% simple interest?

(7) If Donald paid $5400 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(8) Calculate the amount due if Joseph borrowed a sum of $3700 at 8% simple interest for 4 years.

(9) Calculate the amount due if Mary borrowed a sum of $3050 at 4% simple interest for 4 years.

(10) Calculate the amount due after 9 years if Patricia borrowed a sum of $5150 at a rate of 8% simple interest.


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