11.
If log 2 = 0.30103, the number of digits in 264 is:

12.
$${\rm{If}}\,{\log _x}\left( {{9 \over {16}}} \right) = - {1 \over 2},\,{\rm{then}}\,x\,{\rm{is}}\,{\rm{equal}}\,{\rm{to:}}$$

13.
If ax = by, then:

14.
If logx y = 100 and log2 x = 10, then the value of y is: