Simple Interest - Practice Problems

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Here are some Simple Interest Practice Problems. Before Doing Problems, Have a look at the Basics HERE

1.  Find the Simple Interest on Rs 750 in 4 years at 15% per annum

   here S.I =  PTR/100 

                 =  (750 X 4 X 15) / 100 =  450

2. On what sum of money will the Simple Interest be Rs. 2000 in 5 years at 8% Per Annum?

      here they are asking about P, 

         So, P = 100I / TR 

                  =  (100X2000) / 40  = 5000

3. A man invested Rs. 20,000 at 10% P.A. Rs. 15,000 at 12% P.A. and some money at 15% P.A. If the total annual interest recieved is Rs. 56,00, find the money invested by him at 15% P.A                                                                                             
     here, the total Interest he recieved is Rs. 56,00. 
    So,  find the total interest and try to equate it with 56,00

    So, the total interest = Σ [ (PTR)/100 ]    [ here Sigma symbol ( Σ ) represents the Total]

                 = 200X10+150X12+ (P/100)X15 = 5600

                    3800+ (3P/20) = 5600

               = 3P/20  =  1800 => P = 12000/-

4. On a sum of money the rate of interest is 5% Per Annum for the first 3 years, 6% Per Annum for the next 4 years, and 8% Per Annum for the next years beyond the first 7 Years. If the interest obtained in 12 Years is Rs. 3,950, Find the Sum?

   5% X 3 + 6% X 4 + 8% X 5
            =  15% + 24% + 40% = 79%
                =>  (79/100) P  = 3950

                => P  =  (39500/79)  =  5000

5. A sum was put at 5% at a certain rate for 5 Years. Had it been put at 3% Per Annum higher rate, it would have fetched Rs. 900 more. Find the Sum?

  P =   100I / TR      [Note : Here I is Additional Interest and R is additional Rate]

          = (100 X 900) / (5X3)                  
             = 6000

6. On a certain Sum of Money the Simple Interest in 2 years at 10% P.A is Rs. 125, what would be the S.I if the rate of Interest will be 12% P.A in 3 Years?

Here the Principle is same for both the cases. I mean  p = P    

    =>    100i / tr  =  100I / TR

            =  125 / (2 x 10)  =  I / (3 x 12)

          = >  I = 225

7. The S.I on Rs 6400 at 12 1/2 % per annum is Rs. 2000. Find the Period ?

   T = 100I / PR   =  (100 X 2000 X 2) / (6400 X 25)  =  2 1/2 years


8. The S.I on Rs. 6000 in 3 Years and 4 Months is Rs. 3000. Find the rate percent Per Annum ?

    [ here T = 3 4/12 = 3 1/3  = 10/3 years]

          I = PTR / 100 =>  R = 100I / PT

           =>  (100 X 3000 X 3) / (6000 X 10 ) = 15

9. Manish took a loan of Rs. 4000 at S.I. After 2 Years he cleared the loan by paying Rs. 5600. Find the Rate % P.A?

       [ Here Manish took Rs. 4000 and Payed 5600. So the Interest will be 5600-4000 = 1600 ]

      So, R = 100I / PT

                    =  (100 X 1600) / (400 X 2)

                      =  20

10. A lent Rs. 25000 to B for 4 years and Rs. 40,000 to C for 3 1/2 years and got Rs. 24,000 S.I from both B and C. Find the rate PCPA 

     Σ [ (PTR)/100 ]   =  250 X 4R = 400 X (7/2) R =  2400R

                                       => R = 10
 

Check the Basics of Compound Interest HERE