\((1.28 \times 10^{4}) \div (6.4 \times 10^{2})\) equals

  • A \(2 \times 10^{-5}\)
  • B \(2 \times 10^{-1}\)
  • C \(2 \times 10^{1}\)
  • D \(2 \times 10^{-4}\)
jamb 1979mathematics

The correct answer is C. \(2 \times 10^{1}\)

When dividing two numbers in scientific notation, we can divide the coefficients and subtract the exponents to get the result in scientific notation:

\((1.28 \times 10^{4}) \div (6.4 \times 10^{2})\)

=\((1.28 \div 6.4) \times (10^{4} \div 10^{2}) = (2 ) \times (10^{4-2})\)

\((2) \times (10^{2}) = (2) \times (10)\).

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