Aptitude - Logarithm - Discussion
Discussion Forum : Logarithm - General Questions (Q.No. 6)
6.
| If log10 7 = a, then log10 |  |
1 |  |
is equal to: |
| 70 |
Answer: Option
Explanation:
|
= log10 1 - log10 70 | |||||
| = - log10 (7 x 10) | ||||||
| = - (log10 7 + log10 10) | ||||||
| = - (a + 1). |
Discussion:
33 comments Page 2 of 4.
Anbu said:
8 years ago
Nice. Thank you.
Jesha said:
7 years ago
I can't understand how to solve log 10 (70)?
Please, someone explain me.
Please, someone explain me.
Souradeep said:
7 years ago
How to get this? Please explain.
Tanooja said:
7 years ago
log10(1/70) = -log10(70),
= -log10(7*10),
= -(log10(7) + log10(10)) =-(a+1).
= -log10(7*10),
= -(log10(7) + log10(10)) =-(a+1).
Ibrahim said:
6 years ago
2nd and 4th line is not clear. Please explain those.
Rohit said:
5 years ago
By simply log10(1/70) is explained as:
Log (a/b) formula.
Log a-logb
So,
Log10(1) -log10(70).
In this step log10(1) is 0.
So,
0- log10(70)
We write this step in another way as like.
-log10(7*10).
This step is in the form of;
Log (a*b) =log a+ logb.
So,
-[log10(7) +log10(10) ]
Log10(7) =a
And log10(10) =1.
- (a+1).
Log (a/b) formula.
Log a-logb
So,
Log10(1) -log10(70).
In this step log10(1) is 0.
So,
0- log10(70)
We write this step in another way as like.
-log10(7*10).
This step is in the form of;
Log (a*b) =log a+ logb.
So,
-[log10(7) +log10(10) ]
Log10(7) =a
And log10(10) =1.
- (a+1).
Sunder said:
5 years ago
Thank you @Rohit.
Anush said:
1 decade ago
How you got this second step?
Sidhu said:
9 years ago
As we know that,
log10 1 = 0.
And
log x x =1.
log10 (1/70) = lo10 1 - log10 70.
= 0 - log10 70.
= - log10 (7 * 10).
= - (log10 7 + log10 10).
= - (a + 1).
Because log10 7 = a is given and log x x =1.
log10 1 = 0.
And
log x x =1.
log10 (1/70) = lo10 1 - log10 70.
= 0 - log10 70.
= - log10 (7 * 10).
= - (log10 7 + log10 10).
= - (a + 1).
Because log10 7 = a is given and log x x =1.
Prakash said:
10 years ago
log (1/70) = log (1/7*10).
= log (1/7*1/10).
= log (1/7)+log (1/10).
= -log 7-log 10.
= -a-1.
= -(a+1).
= log (1/7*1/10).
= log (1/7)+log (1/10).
= -log 7-log 10.
= -a-1.
= -(a+1).
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers