# CAT – Logarithms

Question:
If log2X + log4X = log0.25and x > 0, then x is
A.  6-1/6
B.  61/6
C.  3-1/3
D.  61/3

Explanation:
log2x + log4x = log0.25
log2x + = log0.25
log2x * = log0.25
log2x * 3 = 2log0.25
log2x3 = log0.256
log2x3 = -log46
log2x3 =
log2x3 =
2log2x3 = -log26
2log2x3 + log26 = 0
log26x6 = 0
6x6 = 1
x6 =
x =  Choice (A).
Level of difficulty 2

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