Question:
Robert took a loan of $4200 at the rate of 7% simple interest per annum. If he paid an amount of $6552 to clear the loan, then find the time period of the loan.
Correct Answer
8
Solution And Explanation
Solution
Given,
Principal (P) = $4200
Rate of Simple Interest (R) = 7% per annum
Amount (A) = $6552
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 = $6552 – $4200 = $2352
Thus, Simple Interest = $2352
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 × 2352/4200 × 7
= 235200/29400
= 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) = $4200
Rate of Simple Interest (R) = 7% per annum
Simple Interest = $2352 (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 $4200
= 7/100 × 4200
= 7 × 4200/100
= 29400/100 = 294
Thus, simple Interest for 1 year = $294
Now,
∵ If the simple Interest is $294, then the time = 1 year
∴ If the simple Interest is $1, then the time = 1/294 years
∴ If the simple Interest is $2352, then the time = 1/294 × 2352 years
= 1 × 2352/294 years
= 2352/294 = 8 years
Thus, time (T) = 8 years Answer
Similar Questions
(1) Calculate the amount due if Patricia borrowed a sum of $3150 at 2% simple interest for 4 years.
(2) Calculate the amount due if Sarah borrowed a sum of $3850 at 9% simple interest for 3 years.
(3) Calculate the amount due after 10 years if David borrowed a sum of $5400 at a rate of 4% simple interest.
(4) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 3% simple interest?
(5) Calculate the amount due if Jessica borrowed a sum of $3750 at 9% simple interest for 4 years.
(6) How much loan did Karen borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6842.5 to clear it?
(7) What amount will be due after 2 years if Andrew borrowed a sum of $3900 at a 8% simple interest?
(8) What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 6% simple interest?
(9) What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 4% simple interest?
(10) What amount will be due after 2 years if William borrowed a sum of $3250 at a 7% simple interest?