Simple Interest
MCQs Math


Question:     In how much time a principal of $3050 will amount to $3660 at a simple interest of 5% per annum?


Correct Answer  4

Solution And Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (R) = 5% per annum

Amount (A) = $3660

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 = $3660 – $3050 = $610

Thus, Simple Interest = $610

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 × 610/3050 × 5

= 61000/15250

= 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) = 5% per annum

Simple Interest = $610 (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 = 5% of Principal

= 5% of $3050

= 5/100 × 3050

= 5 × 3050/100

= 15250/100 = 152.5

Thus, simple Interest for 1 year = $152.5

Now,

∵ If the simple Interest is $152.5, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/152.5 years

∴ If the simple Interest is $610, then the time = 1/152.5 × 610 years

= 1 × 610/152.5 years

= 610/152.5 = 4 years

Thus, time (T) = 4 years Answer


Similar Questions

(1) Find the amount to be paid if Joseph borrowed a sum of $5700 at 3% simple interest for 8 years.

(2) What amount does James have to pay after 6 years if he takes a loan of $3000 at 5% simple interest?

(3) What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 9% simple interest?

(4) Mark took a loan of $6800 at the rate of 8% simple interest per annum. If he paid an amount of $11152 to clear the loan, then find the time period of the loan.

(5) What amount does Joseph have to pay after 6 years if he takes a loan of $3700 at 9% simple interest?

(6) Find the amount to be paid if Karen borrowed a sum of $5950 at 3% simple interest for 8 years.

(7) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 6% simple interest?

(8) If Ashley paid $5460 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(9) Calculate the amount due if David borrowed a sum of $3400 at 4% simple interest for 3 years.

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


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