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CMA Foundation · Fundamentals of Business Mathematics and Statistics · Indices and Logarithms

If log10(x) = 3̄.5000, how many zeros come immediately after the decimal point in x before the first non-zero digit?

There are 2 zeros. A characteristic of 3̄ means x lies between 0.001 and 0.01, specifically x ≈ 0.00316. The number of zeros right after the decimal point equals the absolute value of the characteristic minus one, which is 2.

  1. A3
  2. B1
  3. C2Correct
  4. D4

Explanation

The characteristic 3̄ means -3, so x = 10^-3 × 10^0.5 ≈ 3.16 × 10^-3 = 0.00316. Here there are 2 zeros after the decimal point. The rule is zeros = |characteristic| - 1 = 3 - 1 = 2. Option 3 forgets to subtract 1.

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