Stepwise
Start practisingPractise

JAMB 1993 · UME · Q7

Evaluate without using tables log⁡562.5−log⁡512\log_5 62.5 - \log_5 \frac12.

Worked solution (try it first)
  1. Subtracting logs divides: log⁡562.5−log⁡512=log⁡5(62.5÷0.5)\log_5 62.5 - \log_5 \frac12 = \log_5 (62.5 \div 0.5).
  2. 62.5÷0.5=12562.5 \div 0.5 = 125, and 125=53125 = 5^3.
  3. So the value is log⁡5125=3\log_5 125 = 3, option A.

Report a problem with this question