Please help me to solve this fraction. 
Divide 

 ÷ 

Change these mixed fractions to improper fractions
by this rule:

---------------------------------------------------

To change the mixed number 



to an improper fraction, where W = whole part, 
N = numerator, D = denominator

IMPROPER FRACTION = 

----------------------------------------------------                        

Following the above rule with 

 = 15,  = ,  = 

IMPROPER FRACTION =  =  = 

-----------------------

Following the rule with 

 = 3,  = ,  = 

IMPROPER FRACTION =  =  = 

------------------------

So the original problem

 ÷ 

is now

÷

Now we use the principle of inverting the second fraction
and changing the ÷ to ×

 255      4
----- × ----
  16     15

Cancel the 15 into the 255 and get 17 in the top

  17       
 255      4
----- × ----
  16     15
          1

Cancel the 4 into the 16 and get 4 in the bottom

  17      1           
 255      4
----- × ----
  16     15
   4      1

So you end up eith the improper fraction



Now since the original problem was given
as mixed fractions, we change this to
an improper fraction, by using this rule:

-------------------------------------------

To change the improper fraction  to
a mixed fraction,
 
perform the division
 __ 
D)N

then the mixed fraction will be:

 = 

where  = the numerator,  = the denominator, 
 = the quotient,  = the remainder 

--------------------------------------------
                            __
So we perform the division D)N 

 ` 4
4)17
  16
   1  

Here, N = 17, D = 4, Q = 4, R = 1 so 

 =  becomes

 = 

Edwin