Question:
William took a loan of $5000 at the rate of 7% simple interest per annum. If he paid an amount of $8150 to clear the loan, then find the time period of the loan.
Correct Answer
9
Solution And Explanation
Solution
Given,
Principal (P) = $5000
Rate of Simple Interest (R) = 7% per annum
Amount (A) = $8150
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 = $8150 – $5000 = $3150
Thus, Simple Interest = $3150
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 × 3150/5000 × 7
= 315000/35000
= 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) = $5000
Rate of Simple Interest (R) = 7% per annum
Simple Interest = $3150 (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 $5000
= 7/100 × 5000
= 7 × 5000/100
= 35000/100 = 350
Thus, simple Interest for 1 year = $350
Now,
∵ If the simple Interest is $350, then the time = 1 year
∴ If the simple Interest is $1, then the time = 1/350 years
∴ If the simple Interest is $3150, then the time = 1/350 × 3150 years
= 1 × 3150/350 years
= 3150/350 = 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 6% simple interest for 7 years.
(2) Find the amount to be paid if John borrowed a sum of $5200 at 7% simple interest for 8 years.
(3) How much loan did Betty borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7187.5 to clear it?
(4) Find the amount to be paid if Richard borrowed a sum of $5600 at 2% simple interest for 8 years.
(5) What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 7% simple interest?
(6) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 2% simple interest?
(7) Calculate the amount due if Christopher borrowed a sum of $4000 at 10% simple interest for 3 years.
(8) How much loan did Lisa borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7260 to clear it?
(9) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 10% simple interest for 4 years.
(10) What amount does John have to pay after 5 years if he takes a loan of $3200 at 5% simple interest?