Logarithms Quiz Set 003

Advertisement


Your Score
Correct Answers:
Wrong Answers:
Unattempted:

Question 1

What is the value of log2(128)?

 A

7.

 B

$√7$.

 C

0.

 D

$√128$.

Soln.
Ans: a

Let log2(128) = P. By definition, we have 2P = 128 = 27, which gives 7 as the answer.


Question 2

What is $1/{\text"log"_4(60)}$ + $1/{\text"log"_3(60)}$ + $1/{\text"log"_5(60)}$?

 A

$1$.

 B

5.

 C

12.

 D

0.

Soln.
Ans: a

The given expression simplifies to $\text"log"_60(4)$ + $\text"log"_60(3)$ + $\text"log"_60(5)$ = $\text"log"_60(4 × 3 × 5)$ = $\text"log"_60(60)$ = 1.


Question 3

What is P if $\text"log"_5(4)$ + $\text"log"_5(4P + 1)$ = 1 + $\text"log"_5(P + 4)$?

 A

$1{5/11}$.

 B

$2{7/10}$.

 C

${5/13}$.

 D

$3{10/13}$.

Soln.
Ans: a

We have $\text"log"_5(4)$ + $\text"log"_5(4P + 1)$ = $\text"log"_5(5)$ + $\text"log"_5(P + 4)$. It is same as $\text"log"_5(4 × (4P + 1))$ = $\text"log"_5(5 × (P + 4))$. Equating the logs, $4 × (4P + 1) = 5 × (P + 4)$, solving for P we get P = $1{5/11}$.


Question 4

What is log$7$ + log$1/7$?

 A

0.

 B

$\text"log"_3(7)$.

 C

$\text"log"_7(3)$.

 D

1/2.

Soln.
Ans: a

log(m) + log(1/m) = log (m × $1/m$) = log 1 = 0.


Question 5

What is log$3/4$ + log$4/3$?

 A

0.

 B

$\text"log"_4(3)$.

 C

$\text"log"_3(4)$.

 D

1/2.

Soln.
Ans: a

log(m/n) + log(n/m) = log ($m/n$ × $n/m)$ = log 1 = 0.


buy aptitude video tutorials


Creative Commons License
This Blog Post/Article "Logarithms Quiz Set 003" by Parveen (Hoven) is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Updated on 2017-05-17.

Posted by Parveen(Hoven),
Aptitude Trainer


Advertisement