Aptitude - Logarithm - Discussion
Discussion Forum : Logarithm - General Questions (Q.No. 1)
1.
Which of the following statements is not correct?
Answer: Option
Explanation:
(a) Since loga a = 1, so log10 10 = 1.
(b) log (2 + 3) = log 5 and log (2 x 3) = log 6 = log 2 + log 3
log (2 + 3) 
log (2 x 3)
(c) Since loga 1 = 0, so log10 1 = 0.
(d) log (1 + 2 + 3) = log 6 = log (1 x 2 x 3) = log 1 + log 2 + log 3.
So, (b) is incorrect.
Discussion:
37 comments Page 3 of 4.
Palak Kapoor said:
10 years ago
If a=5 and b=4 then what is the value of log (a-b) (a^2-b^2-2^b)?
Shashi said:
10 years ago
Its awesome.
SSD said:
10 years ago
What is log to the base 5 512?
Garvit said:
10 years ago
Option D can't be considered answer. It's tricky actually:
LHS:
log (1+2+3) = log 6. [1+2+3 = 6].
RHS:
log1 + log2 + log3 = log (1x2x3) = log 6.
Since LHS = RHS (no matter how it comes) D isn't the option.
LHS:
log (1+2+3) = log 6. [1+2+3 = 6].
RHS:
log1 + log2 + log3 = log (1x2x3) = log 6.
Since LHS = RHS (no matter how it comes) D isn't the option.
Suhaas said:
9 years ago
@Palak Kapoor.
The answer is undefined.
log{5 - 4}[5^2 - 4^2 - 4]
log{1}[25 - 16 - 16]
log[25 - 32]
log[- 7]
log value for -ve is undefined.
The answer is undefined.
log{5 - 4}[5^2 - 4^2 - 4]
log{1}[25 - 16 - 16]
log[25 - 32]
log[- 7]
log value for -ve is undefined.
Meenakshi said:
9 years ago
The anwer is absolutely correct according to log properties.
It's log a + log b = log(a * b).
not log(a + b) = log(ab).
It's log a + log b = log(a * b).
not log(a + b) = log(ab).
Keerthana said:
7 years ago
Thanks all for explaining.
Omkar rajale said:
7 years ago
Please explain the option D.
Abhishek said:
7 years ago
The answer B is correct. I agree with it.
Kity said:
7 years ago
How, Please explain this.
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