The value of log2 16 is:
Correct answer B. 4
Topic / 30 questions
Logarithm MCQs
Logarithm MCQs test your use of the rules of logarithms to simplify expressions and find values, often using given values such as log 2 = 0.3010. They appear in NTS, ECAT, SSC and bank aptitude papers. Each question shows its answer instantly, so you can check your working and memorise the key laws.
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If logx y = 100 and log2 x = 10, then the value of y is:
Correct answer C. 21000
If ax = by, then:
Correct answer C. log a/ log b=y/x
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If logx 9/16= -12, then x is equal to:
Correct answer D. 256/81
If log 2 = 0.30103, the number of digits in 264 is:
Correct answer C. 20
If log10 5 + log10 (5x + 1) = log10 (x + 5) + 1, then x is equal to:
Correct answer B. 3
If log10 2 = 0.3010, the value of log10 80 is:
Correct answer B. 1.9030
If log10 2 = 0.3010, then log2 10 is equal to:
Correct answer B. 1000/301
If log a/b + log b/a= log (a + b), then
Correct answer A. a + b = 1
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log 8/ log 8 is equal to:
Correct answer C. 1/2
If log 2 = 0.3010 and log 3 = 0.4771, the value of log5 512 is:
Correct answer C. 3.876
Which of the following logarithm statements is not correct?
Correct answer B. log (2 + 3) = log (2 × 3)
Log2 9 is
Correct answer D. an irrational number
If loge x + loge(1-x) = 0 then
Correct answer B. x2-x+1 = 0
If log81/log3 = x then x is equal to
Correct answer C. 4
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If log100 u = -2 then u =
Correct answer D. 1/10000
Evaluate 3logb a4 x loga b5
Correct answer C. 60
Evaluate log2 (log4 256)
Correct answer A. 2
Evaluate 49log75
Correct answer A. 25
If log2 = 0.3010 log 3 = 0.4771 evaluate |log 3?25/100|
Correct answer D. ?1.534
About Logarithm MCQs
Logarithms are the inverse of powers: if a to the power x equals N, then log of N to base a equals x. Questions in this topic apply the product rule, quotient rule and power rule, change the base of a logarithm, and evaluate expressions such as log 80 using log 2 = 0.3010. Some problems ask for log 10 to base 2, which equals 1 divided by log 2 to base 10. Because many items give approximate values, writing each number as a product of 2, 3, 5 and 10 is usually the quickest route to the answer.
Exams that include Logarithm MCQs
Pakistan
- NTS
- GAT
- ECAT
- ISSB
- FPSC
- PPSC
India
- SSC CGL
- IBPS PO
- SBI PO
- JEE Main
- Campus placements
Bangladesh
- BCS
- Engineering admission (BUET)
- Bank job exams
Frequently asked questions
What are the main rules of logarithms?
The product rule says log(mn) = log m + log n. The quotient rule says log(m/n) = log m minus log n. The power rule says log(m to the power n) = n log m. Also, log of 1 is zero and the log of the base itself is one.
If log 2 = 0.3010, what is log 80?
Write 80 as 8 × 10, which is 2 cubed × 10. Then log 80 = 3 log 2 + log 10 = 3 × 0.3010 + 1 = 1.9030. The same method works for any number that can be broken into powers of 2, 3, 5 and 10.
How many Logarithm MCQs are on MCQs360?
MCQs360 has 30 Logarithm MCQs, all with instant answers and free to practise without sign-up. Work through them after revising the three main laws, and keep a list of common values such as log 2, log 3 and log 5.
Last reviewed October 2026