Use the values for ln $2$ and ln $3$ given in problem 11-25 to evaluate each of the following expressions. Do not use a calculator. 

1. ln $6$ 

   Step 1(a):

   ln$6 =$ ln$(2 · 3)$

   Step 2(a):

   ln$6 =$ ln$2 +$ ln$3$

   Answer (a):

   ln$6 = (0.69315) +$ $(1.0986)$
   ln$6 = 1.7918$

2. ln $12$ 

   Hint (b):

   See part (a).

3. ln $16$ 

   Hint (c):

   See part (a).

4. ln$\frac { 1 } { 3 }$ 

   Step 1(d):

   $\ln\frac{1}{3} = \ln\left(3^{-1}\right)$

   Step 2(d):

   $\ln\frac{1}{3} = -\ln3$