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The product of first 5 terms of a G.P., whose terms are increasing, is 32. The third term of the G.P. is

  • A.2
  • B.\(\frac{1}{2}\)
  • C.4
  • D.\(\frac{1}{8}\)
  • E.8

Answer: A

The third term is 2.

Write the five terms as \(\frac{a}{r^{2}}, \frac{a}{r}, a, ar, ar^{2}\), where \(a\) is the third term. Their product is \(a^{5}\), because the powers of \(r\) cancel:

\[ a^{5} = 32 = 2^{5} \Rightarrow a = 2 \]

The ratio does not matter (the word increasing only says \(r \gt 1\)). 4 and 8 would give products \(4^{5}\) and \(8^{5}\); 1/2 and 1/8 would give products less than 1.

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