The common ratio of a G.P. is 2. If the 5th term is

greater than the 1st term by 45, find the 5th term,

  • A 3
  • B 6
  • C 45
  • D 48
  • E 90
waec 1991mathematics

The correct answer is D. 48

a = 1st term ; ar4 = 5th term

∴ ar4 = a(2)4 = 16a; 16a = 45 + a, a = 3;

3(2)4 = 48

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