logo

CuriousTab

CuriousTab

Discussion


Home Aptitude Linear Equation See What Others Are Saying!
  • Question
  • A man arranges to pay off a debt of ?3600 in 40 annual installments which form an Arithmetic Progression (A.P). When 30 of the installments are paid, he dies leaving one-third of the debt unpaid . Find the value of the first installment.


  • Options
  • A. 55
  • B. 53
  • C. 51
  • D. 49

  • Correct Answer
  • 51 

    Explanation

    Let us assume the first installment is a and difference between two consecutive installments is d.
    According to question,
    Sum of 40 Installments = 3600
    Apply the formula Sum of first n terms in an Arithmetic Progression = Sn = n/2[ 2a + (n?1)d ]
    where a = the first term, d = common difference, n = number of terms.

    n/2[ 2a + (n?1)d ] = 3600
    Put the value of a, n and d from question,
    40/2[ 2a + (40 ?1)d ] = 3600
    20[ 2a + 39d ] = 3600
    [ 2a + 39d ] = 3600/20 = 180
    2a + 39d = 180...........................(1)

    Again according to given question,
    After paying the 30 installments the unpaid amount = 1/3(total unpaid amount) = 3600 x 1/3
    After paying the 30 installments the unpaid amount = 1200
    So After paying the 30 installments the paid amount = 3600 - 1200 = 2400
    Sum of 30 installments = 2400
    30/2[ 2a + (30 ?1)d ] = 2400
    [ 2a + (30 ?1)d ] = 2400 x 2/30
    2a + 29d = 80 x 2 = 160
    2a + 29d = 160..........................(2)
    Subtract the Eq. (2) from Eq. (1), we will get
    2a + 39d - 2a - 29d = 180 - 160
    10d = 20
    d = 2
    Put the value of d in Equation (1), we will get
    2a + 39 x 2 = 180
    2a = 180 - 78
    a = 102/2
    a = 51
    The value of first installment = a = 51


  • More questions

    • 1. 
      Aarti can do a piece of work in 6 days. In how many days will she complete three time of work of same type?

    • Options
    • A. 18 days
    • B. 21 days
    • C. 3 days
    • D. 6 days
    • Discuss
    • 2. 
      750.0003 ÷ 19.999 =?

    • Options
    • A. 49
    • B. 18
    • C. 22
    • D. 38
    • Discuss
    • 3. 
      105, 85, 60, 30, 0, - 45, - 90?

    • Options
    • A. 0
    • B. 85
    • C. -45
    • D. 60
    • Discuss
    • 4. 
      Let A = {1, 2, {3, 4}, 5}. Which of the following statements is true?

    • Options
    • A. {3, 4} ? A
    • B. {3, 4} ? A
    • C. 1 ? A
    • D. {1, 2, 5} ? A
    • Discuss
    • 5. 
      Two vessels A and B contains milk and water mixed in the ratio 5 : 3 and 2 : 3. When these mixtures are mixed to form a new mixture containing half milk and half water, they must be taken in the ratio ?

    • Options
    • A. 2 : 5
    • B. 3 : 5
    • C. 4 : 5
    • D. 7 : 3
    • Discuss
    • 6. 
      1, 2, 4, 8, 16, 32, 64, (...), 256?

    • Options
    • A. 148
    • B. 128
    • C. 154
    • D. 164
    • Discuss
    • 7. 
      A tree is 12 m tall and casts an an 8 m long shadow. At the same time, a flag pole caste a 100 m long shadow. How long is the flag pole?

    • Options
    • A. 150 m
    • B. 200 m
    • C. 125 m
    • D. 115 m
    • Discuss
    • 8. 
      8% of 96 =? of 1/25

    • Options
    • A. 19.2
    • B. 7.68
    • C. 1.92
    • D. None of these
    • Discuss
    • 9. A certain amount earns simple interest of Rs. 1750 after 7 years. Had the interest been 2% more, how much more interest would it have earned?

    • Options
    • A. Rs. 35
    • B. Rs. 245
    • C. Rs. 350
    • D. Cannot be determined
    • E. None of these
    • Discuss
    • 10. 
      If the hands of a clock coincide in every 65 minutes (true time), in 24 hours the clock will gain:

    • Options
    • A. 10 10 minutes. 143
    • B. 9 12 minutes. 143
    • C. 11 12 minutes. 143
    • D. 12 10 minutes. 143
    • Discuss


    Comments

    There are no comments.

Enter a new Comment