6
Q:

Find x if 

A) 0 B) 1
C) 2 D) None of these

Answer:   A) 0

Explanation:

         \inline \log_{\frac{1}{\sqrt{2}}}(1/\sqrt{8})=\log_{2}(4^{x}+1).\log_{2}(4^{x+1}+4)

\inline \Rightarrow     \inline \frac{\log_{2}(1/\sqrt{8})}{\log_{2}(1/\sqrt{2})}=\log_{2}(4^{x}+1).\log_{2}(4^{x+1}+4)

\inline \Rightarrow    \inline 3=\left [ \log_{2}4+\log_{2}(4^{x}+1) \right ]\left [ \log_{2}(4^{x}+1) \right ]

\inline \Rightarrow    (2+t)t = 3,    where t = \inline \log_{2}(4^{x}+1)

\inline \Rightarrow     t = -3, 1

If \inline \log_{2}(4^{x}+1)= -3, then \inline 4^{x}=-7/8 which is not possible

If \inline \log_{2}(4^{x}+1)=1, then \inline 4^{x}+1=2\: \: \: \Rightarrow 4^{x}=1

\inline \Rightarrow               x = 0

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:

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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

 

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6 469
Q:

The Value of   is 

A) -1 B) 0
C) 1/2 D) 1
 
Answer & Explanation Answer: B) 0

Explanation:

                                                                 

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6 511
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.

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4 541
Q:

Find value of 

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

Explanation:

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5 521