"of" means "times"



First we reduce the  to 

Now we have



Now we change the mixed number  to an
improper fraction by multplying the denominator 
by the whole part , getting , adding the  numerator,
getting  and putting that over the denominator , getting 

So now we have



Now multuply the two numerators  getting 
Then multiply the two denominators  getting 

Now put the  over the .

Now we have



That is the improper fraction form of the answer. To get that
to a mixed number,

Divide the denominator  into the numerator 

   4
4)19
  16
   3 

Write the quotient 



Put the remainder  over the divisor , 
getting  and write that beside the , 
and the final answer is



Edwin