Question:
Mark took a loan of $6800 at the rate of 7% simple interest per annum. If he paid an amount of $11084 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) = 7% per annum
Amount (A) = $11084
Thus, time (T) = ?
Method (1) Using Formula
Calculation of Simple Interest, when Principal and Amount are givenFormual 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 = $11084 – $6800 = $4284
Thus, Simple Interest = $4284
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 × 4284/6800 × 7
= 428400/47600
= 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) = 7% per annum
Simple Interest = $4284 (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 = 7% of Principal
= 7% of $6800
= 7/100 × 6800
= 7 × 6800/100
= 47600/100 = 476
Thus, simple Interest for 1 year = $476
Now,
∵ If the simple Interest is $476, then the time = 1 year
∴ If the simple Interest is $1, then the time = 1/476 years
∴ If the simple Interest is $4284, then the time = 1/476 × 4284 years
= 1 × 4284/476 years
= 4284/476 = 9 years
Thus, time (T) = 9 years Answer
Similar Questions
(1) Find the amount to be paid if David borrowed a sum of $5400 at 9% simple interest for 7 years.
(2) Calculate the amount due if James borrowed a sum of $3000 at 7% simple interest for 3 years.
(3) Find the amount to be paid if Sarah borrowed a sum of $5850 at 4% simple interest for 7 years.
(4) If David paid $3808 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.
(5) In how much time a principal of $3150 will amount to $3402 at a simple interest of 4% per annum?
(6) What amount does Mary have to pay after 5 years if he takes a loan of $3050 at 5% simple interest?
(7) Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 9% simple interest.
(8) How much loan did Jacob borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9600 to clear it?
(9) What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 9% simple interest?
(10) What amount does Charles have to pay after 6 years if he takes a loan of $3900 at 8% simple interest?