Simple Interest
MCQs Math


Question:     In how much time a principal of $3050 will amount to $3294 at a simple interest of 2% per annum?


Correct Answer  4

Solution And Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (R) = 2% per annum

Amount (A) = $3294

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 = $3294 – $3050 = $244

Thus, Simple Interest = $244

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 × 244/3050 × 2

= 24400/6100

= 4 years (using formula)

Thus, Time (T) = 4 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) = $3050

Rate of Simple Interest (R) = 2% per annum

Simple Interest = $244 (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 = 2% of Principal

= 2% of $3050

= 2/100 × 3050

= 2 × 3050/100

= 6100/100 = 61

Thus, simple Interest for 1 year = $61

Now,

∵ If the simple Interest is $61, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/61 years

∴ If the simple Interest is $244, then the time = 1/61 × 244 years

= 1 × 244/61 years

= 244/61 = 4 years

Thus, time (T) = 4 years Answer


Similar Questions

(1) Calculate the amount due after 10 years if Karen borrowed a sum of $5950 at a rate of 9% simple interest.

(2) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 10% simple interest?

(3) David took a loan of $4800 at the rate of 6% simple interest per annum. If he paid an amount of $7392 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 6% simple interest.

(5) Find the amount to be paid if Sarah borrowed a sum of $5850 at 8% simple interest for 8 years.

(6) Calculate the amount due if Barbara borrowed a sum of $3550 at 5% simple interest for 4 years.

(7) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 5% simple interest?

(8) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 2% simple interest?

(9) If Barbara paid $3976 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(10) Calculate the amount due if Thomas borrowed a sum of $3800 at 3% simple interest for 4 years.


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©