If log\(_{10}\)2 = 0.3010 and log\(_{10}\)7 = 0.8451, evaluate log\(_{10}\)280

  • A 3.4471
  • B 2.4471
  • C 1.4471
  • D 1.4071
jamb 2009mathematics

The correct answer is B. 2.4471

Log 2 = 0.3010, Log 7 = 0.8451

∴Log 280 = Log 28 x 10

= Log 7x4x10

=Log7 + Log4 + Log10

= Log7 + Log2\(^2\) + Log10

= Log7 + 2Log2 + Log10

= 0.8451 + 2(0.3010) + 1

= 0.8451 + 0.6020 + 1

= 2.4471

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