Question 131496
Here Log8 denotes Log to the base 8.
Log8 (1/256) 
= Log8 (1/2)^8
= 8 Log8 (1/2)
= 8(Log8 1 - Log8 2) 
= 8(0 - Log8 2) 
= - 8/3 Log8 2^3
= - 8/3 Log8 8
= - 8/3