Wednesday, April 8, 2009

GP questions

  1. Find the eight term (ar^7) of the GP 8, 4, 2, ...
  2. If $100 is invested each year at 5% compound interest annually, what would be the total amount of the investment after 10 years.
  3. A GP has a first term of 12 (a = 12) and the fifth term of 18 (ar^4 = 18), find the 13th term (ar^12)
  4. A GP has a second term of 18 (ar=18) and a fourth term of 8 (ar^3=8), find the first term (a) and the common ratio (r)
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3 comments:

  1. AnonymousApril 9, 2009 at 6:54 AM

    (1) 8th term = ar^7
    a=8
    r=4/8=1/2

    8th term = 8(1/2)^7
    =0.0625

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  2. AnonymousApril 9, 2009 at 7:16 AM

    (4) ar =18 ....(1)
    ar^3=8 ....(2)

    eq(2)/eq(1) => ar^3/ar = 8/18
    r^3= 4/9
    r= 0.76

    therefore
    a(0.76)= 18
    a= 23.68

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  3. sky captainApril 11, 2009 at 6:52 AM

    Q. #.1.
    Solution:
    = The 8th term of a GP is = ar^7.
    = a =8.
    = r =4.
    = r/a.
    = 4/8
    = ½
    Therefore the eight term = 8(1/2)^7.
    =0.0625.

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