Question:
Lisa took a loan of $6100 at the rate of 7% simple interest per annum. If he paid an amount of $10370 to clear the loan, then find the time period of the loan.
Correct Answer
10
Solution And Explanation
Solution
Given,
Principal (P) = $6100
Rate of Simple Interest (R) = 7% per annum
Amount (A) = $10370
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 = $10370 – $6100 = $4270
Thus, Simple Interest = $4270
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 × 4270/6100 × 7
= 427000/42700
= 10 years (using formula)
Thus, Time (T) = 10 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) = $6100
Rate of Simple Interest (R) = 7% per annum
Simple Interest = $4270 (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 $6100
= 7/100 × 6100
= 7 × 6100/100
= 42700/100 = 427
Thus, simple Interest for 1 year = $427
Now,
∵ If the simple Interest is $427, then the time = 1 year
∴ If the simple Interest is $1, then the time = 1/427 years
∴ If the simple Interest is $4270, then the time = 1/427 × 4270 years
= 1 × 4270/427 years
= 4270/427 = 10 years
Thus, time (T) = 10 years Answer
Similar Questions
(1) Calculate the amount due if Richard borrowed a sum of $3600 at 2% simple interest for 3 years.
(2) Calculate the amount due if Richard borrowed a sum of $3600 at 10% simple interest for 3 years.
(3) Find the amount to be paid if Michael borrowed a sum of $5300 at 4% simple interest for 7 years.
(4) Jennifer took a loan of $4500 at the rate of 6% simple interest per annum. If he paid an amount of $7200 to clear the loan, then find the time period of the loan.
(5) Calculate the amount due if Jennifer borrowed a sum of $3250 at 6% simple interest for 4 years.
(6) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 4% simple interest.
(7) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 6% simple interest?
(8) Find the amount to be paid if William borrowed a sum of $5500 at 5% simple interest for 8 years.
(9) In how much time a principal of $3100 will amount to $3596 at a simple interest of 4% per annum?
(10) Calculate the amount due if Robert borrowed a sum of $3100 at 3% simple interest for 4 years.