6
Q:

The Value of   is 

A) -1 B) 0
C) 1/2 D) 1

Answer:   B) 0

Explanation:

                                                                 

Q:

A fast moving superfast express crosses another pasenger train in 20 seconds. The speed of faster train is 72 km/hr and speeds of slower train is 27 km/h. Also the length of faster ntrain is 100m, then find the length of the slower train if they are moving in the same direction.

A) 100 m B) 125 m
C) 150 m D) 175 m
 
Answer & Explanation Answer: C) 150 m

Explanation:

Report Error

View Answer Workspace Report Error Discuss

7 496
Q:

For  and  , then which one of the following is correct?

A) P < Q B) P = Q
C) P > Q D) can't be determined
 
Answer & Explanation Answer: C) P > Q

Explanation:

 for (k,l) > 0 and  k > l

Let     k = x+1    and   l = x

 

Report Error

View Answer Workspace Report Error Discuss

6 469
Q:

What is the number of digits in ? Given that log3 = 0.47712?

A) 12 B) 13
C) 14 D) 15
 
Answer & Explanation Answer: B) 13

Explanation:

 Let   

Then ,    

= 27 x 0.47712 = 12.88224

Since the characteristic in the resultant value of log x is 12

 The number of digits in x is (12 + 1) = 13

Hence the required number of digits in  is 13.

Report Error

View Answer Workspace Report Error Discuss

4 541
Q:

Find value of 

A) 1/2 B) 3/2
C) 2 D) 2/3
 
Answer & Explanation Answer: B) 3/2

Explanation:

Report Error

View Answer Workspace Report Error Discuss

5 521
Q:

The least value of expression  for x>1 is:

A) 2 B) 3
C) 4 D) 5
 
Answer & Explanation Answer: C) 4

Explanation:

   \inline 2\log_{10}x-\log_{x}\frac{1}{100}=2\log_{10}x-\frac{\log_{10}10^{-2}}{\log_{10}x}

                                    \inline =2\log_{10}x+\frac{2}{\log_{10}x}

                                    \inline =2\left [ \log_{10}x-\frac{1}{\log_{10}x} \right ]

Since       x >1     \inline \Rightarrow \log_{10}x>0

But since \inline AM\geq GM

\therefore  \inline \frac{\log_{10}x+\frac{1}{\log_{10}x}}{2}\geq \sqrt{\log_{10}x\times \frac{1}{\log_{10}x}}

\inline \Rightarrow   \inline \log_{10}x+\frac{1}{\log_{10}x}\geq 2

\Rightarrow   \inline 2\left [ \log_{10}x+\frac{1}{\log_{10}x} \right ]\geq 4

For x= 10,  \inline 2\left [ \log_{10}x+\frac{1}{\log_{10}x} \right ]\geq 4

Hence the least value of \inline \left [ \log_{10}x-\log_{x}\frac{1}{100} \right ] is 4

Report Error

View Answer Workspace Report Error Discuss

10 526