If log72 = m, then log4928 is equal to ? 1/(1+2m) (1+2m)/2 2m/(2m+1) (2m+1)/2m l

CuriousTab

CuriousTab

Home Aptitude

Discussion

Home ‣ Aptitude ‣ Logarithm See What Others Are Saying!

Question
If log72 = m, then log4928 is equal to ?
Options
A. 1/(1+2m)
B. (1+2m)/2
C. 2m/(2m+1)
D. (2m+1)/2m

Correct Answer

(1+2m)/2

Explanation

$\log_{49} (28) = \frac{1}{2 \log_{7} (7 � 4)}$

= $\frac{1}{2} + \frac{1}{2} (2 \log_{7} (2))$
= $\frac{1}{2} + \log_{7} (2)$
= $\frac{1}{2} + m$
= $\frac{1 + 2 m}{2}$ .

Tags:

More questions

1.
?. x ⁴ ? 227 = 398
?. y ² + 321 = 346
Options
A. 1
B. 2
C. 3
D. 4

2. If 6^th March, 2005 is Monday, what was the day of the week on 6^th March, 2004?
Options
A. Sunday
B. Saturday
C. Tuesday
D. Wednesday

4.
A sum of money is to be divided equally among P, Q and R in the respective ratio of 5 : 6 : 7 and another sum of money is to be divided between S and T equally. If S got ? 2100 less than P, then how much amount did Q receive?
Options
A. ? 2500
B. ? 2000
C. ? 1500
D. Couldn't be determined

5.
If a : b = b : c, then ratio a ⁴ : b ⁴ is equal to
Options
A. ac : b2
B. a2 : c2
C. c2 : a2
D. b2 : ac

6.
A man covers half of his journey at 6 km/h and the remaining half at 3 km/h. Find his average speed.
Options
A. 3 km/h
B. 4 km/h
C. 4.5 km/h
D. 9 km/h

7.
A person can walk a certain distance and drive back in 6 h. He can also walk both ways in 10 h. How much time will he take to drive both ways?
Options
A. 2 h
B. 21/2 h
C. 51/2 h
D. 4 h

8.
Find the least number by which 175760 be devided to make it a perfect cube.
Options
A. 10
B. 20
C. 100
D. 5

9.
The roots of the equation x² + px + q = 0 are equal if :
Options
A. p2 = 2q
B. p2 = 4q
C. p2 = - 4q
D. p2 = - 2q

10.
Two cubes have volumes in the ratio 1: 27, The ratio of their surface areas is?
Options
A. 1 : 3
B. 1 : 8
C. 1 : 9
D. 1 : 18

Comments

More in Aptitude: