Simple Interest
MCQs Math


Question:     Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $6314 to clear the loan, then find the time period of the loan.


Correct Answer  9

Solution And Explanation

Solution

Given,

Principal (P) = $4100

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

Amount (A) = $6314

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 = $6314 – $4100 = $2214

Thus, Simple Interest = $2214

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 × 2214/4100 × 6

= 221400/24600

= 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) = $4100

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

Simple Interest = $2214 (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 $4100

= 6/100 × 4100

= 6 × 4100/100

= 24600/100 = 246

Thus, simple Interest for 1 year = $246

Now,

∵ If the simple Interest is $246, then the time = 1 year

∴ If the simple Interest is $1, then the time = 1/246 years

∴ If the simple Interest is $2214, then the time = 1/246 × 2214 years

= 1 × 2214/246 years

= 2214/246 = 9 years

Thus, time (T) = 9 years Answer


Similar Questions

(1) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 2% simple interest.

(2) How much loan did Ryan borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9480 to clear it?

(3) Find the amount to be paid if Susan borrowed a sum of $5650 at 7% simple interest for 8 years.

(4) Calculate the amount due if David borrowed a sum of $3400 at 10% simple interest for 4 years.

(5) What amount does Elizabeth have to pay after 5 years if he takes a loan of $3450 at 8% simple interest?

(6) Calculate the amount due if Susan borrowed a sum of $3650 at 2% simple interest for 3 years.

(7) Find the amount to be paid if Michael borrowed a sum of $5300 at 4% simple interest for 8 years.

(8) Christopher took a loan of $6000 at the rate of 8% simple interest per annum. If he paid an amount of $10320 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due if Barbara borrowed a sum of $3550 at 8% simple interest for 3 years.

(10) Michael took a loan of $4600 at the rate of 8% simple interest per annum. If he paid an amount of $6808 to clear the loan, then find the time period of the loan.


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