Answer:
(b) 2.68
Explanation:
Your question has a link to a suitable calculator. All you need to do is make use of it. It tells you log₅(75) ≈ 2.68.
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Other ways to look at the problem
If you recall that a logarithm represents an exponent of the base, you can ask yourself, what power 5 must be raised to in order to get 75. You know that 5^2 = 25, and 5^3 = 125, so the power will have to be between 2 and 3. There is only one answer choice in that range: 2.68.
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The rules of logarithms let you rewrite the given expression as ...
log₅(75) = log₅(3×5²) = log₅(3) +2·log₅(5) = log₅(3) +2
The log₅ of any number between 1 and 5 will be a positive fraction, so this sum must be between 2 and 3.