CA Foundation P3 · Chapter 1 · Question 7 of 9
Given log 2 = 0.3010 and log 3 = 0.4771, the value of log 72 is:
Test yourself: pick an answer
Reveal answer & explanation
Correct answer: A) 1.8572
Explanation
72 = 8 x 9 = 2³ x 3². So log 72 = 3 log 2 + 2 log 3 = 3(0.3010) + 2(0.4771) = 0.9030 + 0.9542 = 1.8572. Taking 3² as 3 gives 1.3801, and swapping the powers (2² x 3³ = 108) gives 2.0333.
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