Simple Interest
MCQs Math


Question:     In how much time a principal of $3100 will amount to $3596 at a simple interest of 4% per annum?


Correct Answer  4

Solution And Explanation

Solution

Given,

Principal (P) = $3100

Rate of Simple Interest (R) = 4% per annum

Amount (A) = $3596

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 = $3596 – $3100 = $496

Thus, Simple Interest = $496

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 × 496/3100 × 4

= 49600/12400

= 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) = $3100

Rate of Simple Interest (R) = 4% per annum

Simple Interest = $496 (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 = 4% of Principal

= 4% of $3100

= 4/100 × 3100

= 4 × 3100/100

= 12400/100 = 124

Thus, simple Interest for 1 year = $124

Now,

∵ If the simple Interest is $124, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/124 years

∴ If the simple Interest is $496, then the time = 1/124 × 496 years

= 1 × 496/124 years

= 496/124 = 4 years

Thus, time (T) = 4 years Answer


Similar Questions

(1) If Richard borrowed $3600 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(2) Lisa took a loan of $6100 at the rate of 7% simple interest per annum. If he paid an amount of $8662 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due if James borrowed a sum of $3000 at 6% simple interest for 3 years.

(4) What amount will be due after 2 years if Matthew borrowed a sum of $3600 at a 5% simple interest?

(5) In how much time a principal of $3050 will amount to $3294 at a simple interest of 4% per annum?

(6) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 4% simple interest?

(7) Calculate the amount due if Michael borrowed a sum of $3300 at 10% simple interest for 4 years.

(8) How much loan did Betty borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7812.5 to clear it?

(9) Calculate the amount due if Joseph borrowed a sum of $3700 at 10% simple interest for 3 years.

(10) Sarah took a loan of $5700 at the rate of 10% simple interest per annum. If he paid an amount of $11400 to clear the loan, then find the time period of the loan.


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