Simple Interest
MCQs Math


Question:     Lisa took a loan of $6100 at the rate of 6% simple interest per annum. If he paid an amount of $9394 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $6100

Rate of Simple Interest (R) = 6% per annum

Amount (A) = $9394

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 = $9394 – $6100 = $3294

Thus, Simple Interest = $3294

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 × 3294/6100 × 6

= 329400/36600

= 9 years (using formula)

Thus, Time (T) = 9 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) = $6100

Rate of Simple Interest (R) = 6% per annum

Simple Interest = $3294 (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 = 6% of Principal

= 6% of $6100

= 6/100 × 6100

= 6 × 6100/100

= 36600/100 = 366

Thus, simple Interest for 1 year = $366

Now,

∵ If the simple Interest is $366, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/366 years

∴ If the simple Interest is $3294, then the time = 1/366 × 3294 years

= 1 × 3294/366 years

= 3294/366 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) William took a loan of $5000 at the rate of 8% simple interest per annum. If he paid an amount of $7400 to clear the loan, then find the time period of the loan.

(2) What amount does James have to pay after 5 years if he takes a loan of $3000 at 4% simple interest?

(3) In how much time a principal of $3050 will amount to $3812.5 at a simple interest of 5% per annum?

(4) What amount does Charles have to pay after 6 years if he takes a loan of $3900 at 6% simple interest?

(5) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 8% simple interest?

(6) Michael took a loan of $4600 at the rate of 6% simple interest per annum. If he paid an amount of $7360 to clear the loan, then find the time period of the loan.

(7) Elizabeth took a loan of $4900 at the rate of 6% simple interest per annum. If he paid an amount of $7546 to clear the loan, then find the time period of the loan.

(8) In how much time a principal of $3150 will amount to $3937.5 at a simple interest of 5% per annum?

(9) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 2% simple interest?

(10) Find the amount to be paid if Thomas borrowed a sum of $5800 at 9% simple interest for 8 years.


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