Simple Interest
MCQs Math


Question:     Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $11730 to clear the loan, then find the time period of the loan.


Correct Answer  10

Solution And Explanation

Solution

Given,

Principal (P) = $6900

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

Amount (A) = $11730

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 = $11730 – $6900 = $4830

Thus, Simple Interest = $4830

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 × 4830/6900 × 7

= 483000/48300

= 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) = $6900

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

Simple Interest = $4830 (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 $6900

= 7/100 × 6900

= 7 × 6900/100

= 48300/100 = 483

Thus, simple Interest for 1 year = $483

Now,

∵ If the simple Interest is $483, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/483 years

∴ If the simple Interest is $4830, then the time = 1/483 × 4830 years

= 1 × 4830/483 years

= 4830/483 = 10 years

Thus, time (T) = 10 years Answer


Similar Questions

(1) Robert took a loan of $4200 at the rate of 7% simple interest per annum. If he paid an amount of $5964 to clear the loan, then find the time period of the loan.

(2) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 6% simple interest?

(3) Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 7% simple interest.

(4) Find the amount to be paid if Robert borrowed a sum of $5100 at 7% simple interest for 7 years.

(5) What amount does Mary have to pay after 5 years if he takes a loan of $3050 at 7% simple interest?

(6) How much loan did Donna borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8562.5 to clear it?

(7) Calculate the amount due if Michael borrowed a sum of $3300 at 4% simple interest for 3 years.

(8) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 2% simple interest.

(9) What amount will be due after 2 years if Thomas borrowed a sum of $3400 at a 7% simple interest?

(10) Calculate the amount due after 10 years if Sarah borrowed a sum of $5850 at a rate of 7% simple interest.


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