Simple Interest - Problems and Answers with Detailed Explanation

Today I am going to share practice questions for Simple Interest. Must download read SI and CI concepts here.

  1. On what sum of money lent out at 9% per annum simple interest for 6 years does the simple interest amount to Rs. 810?(RBI'82)
  2. A sum of Rs. 800 amounts to Rs. 920 in 3 years at simple interest. If the interest rate is increased by 3%, it would amount to how much ?
  3. A sum was put at simple interest at a certain rate for 3 years. Had it been put at 2% higher rate, it would have fetched Rs. 360 more. Find the sum.
  4. The simple interest on a sum of money is 4/9 of the principal. Find the rate percent and time, if both are numerically equal.(S.S.C. 2000)
  5. At what rate of interest per annum will a sum double itself in 8 years? ( Bank PO'86)
  6. At what rate percent per annum will a sum of money double in 16 years? ( R.R.B. 2003)
  7. A sum when reckoned at simple interest 21/2% per annum amounts to Rs. 630 after 2 years. Find the sum.
  8. A sum of Rs. 2 is lent to be paid back in 3 equal monthly installments of Re. 1 each. Find the rate per cent .
  9. What annual installment will discharge a debt of Rs. 1092 due in 3 years at 12% simple interest 
  10. What annual installment will discharge a debt of Rs 4,200 due in 5 years at 10% simple interest ? (AAO '82)
  11. A sum of Rs. 3,800 is lent out in two parts in such a way that the interest on one part at 8% for 5 years is equal to that on another part at 1/2% for 15 years. Find the sum lent out at 8%.
  12. A sum of Rs. 1550 is lent out into two parts, one at 8% and another one at 6%. If the total annual income is Rs. 106, find the money lent at each rate.(L.I.C. A.A.O 2003)
  13. If rs. 85 amounts to Rs. 95 in 3 years, what Rs. 102 will amount to in 5 years at the same rate percent?

# Solution 

1. 1500
r×t = S.I/Principal×100 ⇒9×6 = 810/P×100 ⇒ 81000/54 ⇒ 1500

2. 992
S.I = Amount - Principal ⇒S.I = 920 - 800 = 120⇒  r×t = S.I/Principal×100 ⇒ r×3 = 120/800 ×100
r = 5% ⇒ Now r+3% ⇒ 5+3 = 8% ⇒  r×t = S.I/Principal×100 ⇒ 8×3 = S.I/800 ×100 ⇒192
⇒ 800+192
⇒ 992

3. 6000
⇒ [P×(R+2)×3/100] = [P×(R+2)×3/100] = 360
⇒ 3PR + 6P - 3PR = 36000 ⇒ 6P = 36000 ⇒ P = 6000

4. R = 62/3% T= 6 yrs 8 months
⇒  r×t = S.I/Principal×100 ⇒ R×R = 4x/9/x×100 ⇒ R2 = 400x/9
⇒ R = 20/3

5. R= 12 1/2%
S.I=A-P ⇒ Let P = x ⇒SI = 2x - x ⇒ S.I = x
⇒  r×t = S.I/Principal×100 ⇒ r×8= x/x×100 ⇒ R = 100/8

6. R = 61/4 % ( Same As Q5.)

7. P = 600
A = P + S.I
⇒ A = P + [ 1+ RT/100  ]
⇒ 630 = P [ 1+ 2×5/100×2] ⇒630 = P × 105/108 ⇒ P = 600

8. 400%
Borrowed ( debt) amount = M, n = no. of installments , amount of equal installments = x ,
rate of percent = r (quarterly = r/4 % , monthly = r/12 % ).
M = nx [ 1 + r(n-1)/ 200 ]
2 = 3×1 [ 1 + r(3-1)/200×12 ]
⇒x =400 %

9. Rs.325 (Same As Q 8&10)

10. 700 per year
M = nx [ 1 + r(n-1)/ 200 ]
Here, M = Rs. 4200, n = 5 , y = 1 , r  = 10% , x = annual installment = ?
4200 = 5x [ 1 + 10×4 /200 ]
x = Rs. 700 per year.

11. P = Rs. 600
Let the sum lent out at 8% = P1 ; sum lent out at 1/2 % = P2 [since (SI)1 = (SI)2 ]
P1 × 8×5 =P2 × 1/2 ×15 ⇒ P1/P2 = 15/2*8*5 = 3/16
P1 = Sum lent out at 8% = 3/(3+16) ⇒ 3800 = Rs. 600

12. 900

13. A = 122

    Smart Prep Kit for Banking Exams by Ramandeep Singh - Download here


    Join 40,000+ readers and get free notes in your email

    14 comments:

    1. wts dis 5 Ps?? heard of only 4 Ps & 7 Ps

      ReplyDelete
    2. in Q6 wts "question marks"?

      ReplyDelete
    3. Read this - http://www.inc.com/theupsstore/the-five-ps-of-marketing-product-place-promotion-price-and-profit.html

      ReplyDelete
    4. ok so its product price promotion place & profit, but sir in the ques given above, der is 1 option as "people", i think both d pakaging & people sud be the ans den. Am confused..somwhr the 5th P is given as profit.. smwhr its people

      ReplyDelete
    5. thank u sir :) sir if possible provide us english quiz of spotting error also plz sir....

      ReplyDelete
    6. Sir, Any idea about SBI Associates clerk take home salary ?

      ReplyDelete
    7. Packaging is not part of 5 Ps rather it's part of 7 Ps as defined by CIM

      ReplyDelete
    8. ROHIT DHULL GEORGIANJuly 20, 2015 at 6:30 PM

      Good one sir. .
      I m a constant reader of bank exam site and Raman sir doing good.
      Please provide pdf of English exams relatirrelating spotting errors synonym antonyms erc

      ReplyDelete
    9. sir good i am proper follow your site

      ReplyDelete
    10. Sir you Very simple methods and tricks. Its very useful to me

      ReplyDelete
    11. pls explain 8th problem

      ReplyDelete
    12. Plz explain ques 12?

      ReplyDelete

    Thanks for commenting. Follow us on Telegram. Search BankExamsToday