Simple Interest
MCQs Math


Question:     Patricia took a loan of $4300 at the rate of 7% simple interest per annum. If he paid an amount of $6407 to clear the loan, then find the time period of the loan.


Correct Answer  7

Solution And Explanation

Solution

Given,

Principal (P) = $4300

Rate of Simple Interest (R) = 7% per annum

Amount (A) = $6407

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 = $6407 – $4300 = $2107

Thus, Simple Interest = $2107

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 × 2107/4300 × 7

= 210700/30100

= 7 years (using formula)

Thus, Time (T) = 7 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) = $4300

Rate of Simple Interest (R) = 7% per annum

Simple Interest = $2107 (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 $4300

= 7/100 × 4300

= 7 × 4300/100

= 30100/100 = 301

Thus, simple Interest for 1 year = $301

Now,

∵ If the simple Interest is $301, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/301 years

∴ If the simple Interest is $2107, then the time = 1/301 × 2107 years

= 1 × 2107/301 years

= 2107/301 = 7 years

Thus, time (T) = 7 years Answer


Similar Questions

(1) Calculate the amount due if Christopher borrowed a sum of $4000 at 10% simple interest for 3 years.

(2) What amount does Christopher have to pay after 6 years if he takes a loan of $4000 at 6% simple interest?

(3) Find the amount to be paid if William borrowed a sum of $5500 at 4% simple interest for 8 years.

(4) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 6% simple interest?

(5) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 5% simple interest.

(6) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 3% simple interest?

(7) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 8% simple interest?

(8) Find the amount to be paid if James borrowed a sum of $5000 at 10% simple interest for 7 years.

(9) James had to pay $3270 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(10) How much loan did Kenneth borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8750 to clear it?


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