Simple Interest
MCQs Math


Question:     Sarah took a loan of $5700 at the rate of 9% simple interest per annum. If he paid an amount of $10830 to clear the loan, then find the time period of the loan.


Correct Answer  10

Solution And Explanation

Solution

Given,

Principal (P) = $5700

Rate of Simple Interest (R) = 9% per annum

Amount (A) = $10830

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 = $10830 – $5700 = $5130

Thus, Simple Interest = $5130

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 × 5130/5700 × 9

= 513000/51300

= 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) = $5700

Rate of Simple Interest (R) = 9% per annum

Simple Interest = $5130 (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 = 9% of Principal

= 9% of $5700

= 9/100 × 5700

= 9 × 5700/100

= 51300/100 = 513

Thus, simple Interest for 1 year = $513

Now,

∵ If the simple Interest is $513, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/513 years

∴ If the simple Interest is $5130, then the time = 1/513 × 5130 years

= 1 × 5130/513 years

= 5130/513 = 10 years

Thus, time (T) = 10 years Answer


Similar Questions

(1) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 2% simple interest?

(2) Find the amount to be paid if Linda borrowed a sum of $5350 at 4% simple interest for 8 years.

(3) Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 8% simple interest.

(4) If Richard paid $4320 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(5) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 7% simple interest?

(6) How much loan did Brian borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9000 to clear it?

(7) Betty took a loan of $6500 at the rate of 6% simple interest per annum. If he paid an amount of $8840 to clear the loan, then find the time period of the loan.

(8) What amount will be due after 2 years if Paul borrowed a sum of $3850 at a 6% simple interest?

(9) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 7% simple interest?

(10) If Charles borrowed $3900 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.


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