Simple Interest
MCQs Math


Question:     Mark took a loan of $6800 at the rate of 6% simple interest per annum. If he paid an amount of $10472 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $6800

Rate of Simple Interest (R) = 6% per annum

Amount (A) = $10472

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 = $10472 – $6800 = $3672

Thus, Simple Interest = $3672

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 × 3672/6800 × 6

= 367200/40800

= 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) = $6800

Rate of Simple Interest (R) = 6% per annum

Simple Interest = $3672 (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 = 6% of Principal

= 6% of $6800

= 6/100 × 6800

= 6 × 6800/100

= 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 $3672, then the time = 1/408 × 3672 years

= 1 × 3672/408 years

= 3672/408 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) Thomas took a loan of $5600 at the rate of 7% simple interest per annum. If he paid an amount of $9128 to clear the loan, then find the time period of the loan.

(2) If James paid $3480 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(3) Find the amount to be paid if Mary borrowed a sum of $5050 at 6% simple interest for 7 years.

(4) Find the amount to be paid if Christopher borrowed a sum of $6000 at 3% simple interest for 7 years.

(5) Find the amount to be paid if Charles borrowed a sum of $5900 at 2% simple interest for 8 years.

(6) Find the amount to be paid if Richard borrowed a sum of $5600 at 7% simple interest for 7 years.

(7) Calculate the amount due after 10 years if David borrowed a sum of $5400 at a rate of 10% simple interest.

(8) Robert took a loan of $4200 at the rate of 6% simple interest per annum. If he paid an amount of $6468 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due if Robert borrowed a sum of $3100 at 4% simple interest for 4 years.

(10) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 8% simple interest?


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