Simple Interest
MCQs Math


Question:     Matthew took a loan of $6400 at the rate of 6% simple interest per annum. If he paid an amount of $9088 to clear the loan, then find the time period of the loan.


Correct Answer  7

Solution And Explanation

Solution

Given,

Principal (P) = $6400

Rate of Simple Interest (R) = 6% per annum

Amount (A) = $9088

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 = $9088 – $6400 = $2688

Thus, Simple Interest = $2688

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 × 2688/6400 × 6

= 268800/38400

= 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) = $6400

Rate of Simple Interest (R) = 6% per annum

Simple Interest = $2688 (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 = 6% of Principal

= 6% of $6400

= 6/100 × 6400

= 6 × 6400/100

= 38400/100 = 384

Thus, simple Interest for 1 year = $384

Now,

∵ If the simple Interest is $384, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/384 years

∴ If the simple Interest is $2688, then the time = 1/384 × 2688 years

= 1 × 2688/384 years

= 2688/384 = 7 years

Thus, time (T) = 7 years Answer


Similar Questions

(1) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 10% simple interest.

(2) Calculate the amount due if David borrowed a sum of $3400 at 5% simple interest for 4 years.

(3) Calculate the amount due if Richard borrowed a sum of $3600 at 7% simple interest for 3 years.

(4) What amount does Joseph have to pay after 6 years if he takes a loan of $3700 at 5% simple interest?

(5) What amount does Christopher have to pay after 6 years if he takes a loan of $4000 at 4% simple interest?

(6) How much loan did Melissa borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8452.5 to clear it?

(7) If Richard paid $4176 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(8) What amount does James have to pay after 5 years if he takes a loan of $3000 at 4% simple interest?

(9) Calculate the amount due if Joseph borrowed a sum of $3700 at 5% simple interest for 3 years.

(10) Patricia had to pay $3433.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.


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