120
Q:

# If log 2 = 0.3010 and log 3 = 0.4771, the values of log5 512 is

 A) 2.875 B) 3.875 C) 4.875 D) 5.875

Explanation:

ANS:      log5512 = log512/log5  =  $log29log10/2$  =$9log2log10-log2$ =$9*0.30101-0.3010$ =2.709/0.699 =2709/699 =3.876

Q:

Solve the equation  ?

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

Explanation:

Rewrite equation as

Leads to 2x + 1 = 0

Solve for x : x = -1/2

14 2028
Q:

If $log72$ = m, then $log4928$ is equal to ?

 A) 1/(1+2m) B) (1+2m)/2 C) 2m/(2m+1) D) (2m+1)/2m

Explanation:

= $12+122log72$
= $12+log72$

$1+2m2$.

27 3380
Q:

If  , then

 A) 1 B) 2 C) 4 D) 8

Explanation:

Given

Now

$logbc2-a2$

15 2140
Q:

If log 64 = 1.8061, then the value of log 16 will be (approx)?

 A) 1.9048 B) 1.2040 C) 0.9840 D) 1.4521

Explanation:

Given that, log 64 = 1.8061

i.e $log43=1.8061$

--> 3 log 4 = 1.8061

--> log 4 = 0.6020

--> 2 log 4 = 1.2040

$⇒log42=1.2040$

Therefore, log 16 = 1.2040

26 6010
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

Explanation:

$20=(100+x)252$

$⇒$ X=150m

26 3192
Q:

For ,  and  $p=logxx+1$$q=logx+1x+2$ then which one of the following is correct?

 A) p < q B) p = q C) p > q D) can't be determined

Explanation:

$kl>k+1l+1$ for (k,l) > 0 and  k > l

Let     k = x+1    and   l = x

Therefore, $x+1x>(x+1)+1(x)+1$

(x + 1) > x

Therefore, $log(x+1)log(x)>log(x+2)log(x+1)$

17 2290
Q:

The Value of  $logtan10+logtan20+⋯⋯+logtan890$ is

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

Explanation:

= log 1 + log 1 +.....+log 1

= 0.

18 2296
Q:

What is the number of digits in $333$? Given that log3 = 0.47712?

 A) 12 B) 13 C) 14 D) 15

Explanation:

Let   $333$

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 $333$is 13.