RPF Constable practice question
If log 2 = 0.3010 and log 3 = 0.4771, then the value of log 150 is:
From a RPF Constable Quantitative Aptitude practice set · Quantitative Aptitude
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Correct answer: (C) 2.1761
Factorise the argument: 150 = 21 × 31 × 52. Using log (mn) = log m + log n and log (mᵏ) = k log m, log 150 = log 2 + log 3 + 2 log 5. Substituting the given values: 1 × 0.3010 + 1 × 0.4771 + 2 × 0.6990 = 2.1761. (log 5 = log 10 − log 2 = 1 − 0.3010 = 0.6990.)
हिंदी में प्रश्न
यदि log 2 = 0.3010 और log 3 = 0.4771 हो, तो log 150 का मान है:
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सही उत्तर: (C) 2.1761
पहले संख्या का गुणनखंड करें: 150 = 21 × 31 × 52। log (mn) = log m + log n तथा log (mᵏ) = k log m के नियम से, log 150 = log 2 + log 3 + 2 log 5। दिए गए मान रखने पर: 1 × 0.3010 + 1 × 0.4771 + 2 × 0.6990 = 2.1761। (log 5 = log 10 − log 2 = 1 − 0.3010 = 0.6990।)
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