This set of Aptitude Questions and Answers (MCQs) focuses on “Logarithms”. These questions are beneficial for various competitive exams, placement interviews, and entrance tests.
1. Given log103 = 0.477, what should be the value of log1090?
a) 0.954
b) 0.977
c) 1.954
d) 3.908
View Answer
Explanation: Given, log103 = 0.477.
log1081 = log10 (9 * 10)
= log109 + log1010
= log10(32) + 1
= 2log103 + 1
= (2 * 0.477) + 1
= 0.954 + 1
= 1.954
2. Let log105 = z, then what should be the value of log10(1/50)?
a) -(z + 1)
b) -(z2 + 2)
c) (z + 1)-1
d) (z + 1)/(z – 1)
View Answer
Explanation: Given,
log105 = z
log10 (1/50) = log101 – log1050
= -log10 (5 * 10)
= -(log105 + log1010)
= -(z + 1)
3. If xa = yb, then which of the following options is correct?
a) log y/log x = b/a
b) log x/log y = b/a
c) log x/log y = a/b
d) log a/log b = y/x
View Answer
Explanation: Given,
xa = yb
Then,
➩ log xa = log yb
➩ a log x = b log y
➩ log x/log y = b/a
4. What should be the value of log10 (0.0000001)?
a) -7
b) 7
c) -1/7
d) -1
View Answer
Explanation: log10 (0.0000001) = log10 (1/10000000)
= log10 (1/107)
= log10 (10-7)
= -7 log1010
= -7 * 1
= -7
5. What could be the value of x, if log2[log2 (log4 x)] = 1?
a) 128
b) 512
c) 256
d) 1024
View Answer
Explanation: Given,
log3[log4 (log2 x)] = 1
➩ log2(log4 x) = 21 = 2
➩ log4 x = 22 = 4
➩ x = 44
➩ x = 256
6. What could be the value of z to satisfy log1020 + log105 = z?
a) 10
b) 1/10
c) 1/2
d) 2
View Answer
Explanation: Given,
log1020 + log105 = z
Thus, z = log10 (20 * 5).
➩ z = log10 (100)
➩ z = log10 (10)2
➩ z = 2 log1010
➩ z = 2(1) = 2
7. Which of the following options can be equated to (log10√9)/(log109)?
a) 1/2
b) 1/3
c) 3
d) 1/9
View Answer
Explanation: (log10√9)/(log109) = [log10 (9)1/2]/[log10 9]
= \((\frac {1}{2})\) (log10 9)/(log10 9)
= 1/2
8. What should be the simplified value of log2√3 (1/12)?
a) 3
b) – 4
c) 2
d) – 2
View Answer
Explanation: log2√3 (1/12) = log2√3 (1/(2√3)2)
= log2√3/((2√3)-2)
= -2(log2√3 2√3)
= -2
9. If log1000X = -1/3, then which value of X from the options given below would satisfy this equation?
a) 10
b) 1/10
c) -1/10
d) -1/100
View Answer
Explanation: Given,
log1000X = -1/3
➩ X = (1000)-1/3
➩ X = (103)-1/3
➩ X = 10-1
➩ X = 1/10
10. What would be the value of x, if log10(x – 10) = 1?
a) 20
b) 10
c) 100
d) 90
View Answer
Explanation: Given,
log10(x – 10) = 1
log10(x – 10) = log1010
➩ x – 10 = 10
➩ x = 10 + 10
➩ x = 20
More Aptitude Questions and Answers on Logarithms:
- Logarithms Questions (Set 2)
- Logarithms Questions (Set 3)
- Logarithms Questions (Set 4)
- Logarithms Questions (Set 5)
- Logarithms Questions (Set 6)
- Logarithms Questions (Set 7)
- Logarithms Questions (Set 8)
- Logarithms Questions (Set 9)
- Logarithms Questions (Set 10)
To practice all aptitude questions, please visit “1000+ Quantitative Aptitude Questions”, “1000+ Logical Reasoning Questions”, and “Data Interpretation Questions”.
