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

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

13.
If ax = by, then:

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