Question Text
Question 12 :
If $2^x - {2^{x - 1}} = 4$ then $x^x$ is equals to 
Question 13 :
Compare the size of a pen tip which is $0.000005$ m to that of the width of pen which is $ 0.0000249$ m.
Question 14 :
If $64^{x} = 4^{x^{2} - 4}$, then find the value of $x$.
Question 16 :
If $5^{k^2}(25^{2k})(625) = 25\sqrt{5}$ and $k < -1$, find the value of $k$.
